Author name code: kashapova ADS astronomy entries on 2022-09-14 author:"Kashapova, Larisa K." ------------------------------------------------------------------------ Title: Analysis of the Properties of SEP Events and Their Solar Sources Taking Into Account of the Magneto-Morphological Classification of Active Regions Authors: Kashapova, L. K.; Zhukova, A. V.; Miteva, R.; Zhdanov, D. A.; Myagkova, I. N.; Meshalkina, N. S. Bibcode: 2021Ge&Ae..61.1022K Altcode: We studied 87 events of solar cosmic rays, i.e., solar energetic particle (SEP) emissions associated with solar flares of at least M5 class (according to the GOES classification) that occurred during solar cycle 23. A relationship between the spectral parameters of the SEP events and the microwave (MW) emission properties of the related solar flares was analysed. The peak frequency of the MW spectrum was used as an indicator of the acceleration processes during solar flares, which may characterize both the strength of magnetic field in the emission source and the intensity of the accelerated particle flux. The magneto-morphological classification (MMC) was applied to take into account the features of the magnetic topology of the active regions (ARs) that generated flares. Our analysis showed that most of ARs, associated with SEP events with large proton flux, violated at least one of the empirical laws established for sunspot groups (Hale's law, Joy's law, or another). The relationships between the spectral properties of electrons and protons and the properties of MW radiation were analyzed and discussed, taking into account the MMC of ARs generated flares associated with SEP events. Title: Common Origin of Quasi-Periodic Pulsations in Microwave and Decimetric Solar Radio Bursts Authors: Kashapova, Larisa K.; Kolotkov, Dmitrii Y.; Kupriyanova, Elena G.; Kudriavtseva, Anastasiia V.; Tan, Chengming; Reid, Hamish A. S. Bibcode: 2021SoPh..296..185K Altcode: 2021arXiv211007880K We analyse quasi-periodic pulsations (QPP) detected in the microwave and decimetre radio emission of the 5 May 2017 7:04 UT (SOL2017-09-05T07:04) solar flare, using simultaneous observations by the Siberian Radioheliograph 48 (SRH-48, 4 - 8 GHz) and Mingantu Spectral Radioheliograph (MUSER-I, 0.4 - 2 GHz). The microwave emission was broadband with a typical gyrosynchrotron spectrum, while a quasi-periodic enhancement of the decimetric emission appeared in a narrow spectral band (500 - 700 MHz), consistent with the coherent-plasma-emission mechanism. The periodicity that we found in microwaves is about 30 seconds, coming from a compact loop-like source with a typical height of about 31 Mm. The decimetric emission exhibited a periodicity of about 6 seconds. We suggest a qualitative scenario linking the QPPs observed in both incoherent and coherent spectral bands and their generation mechanisms. The properties of the QPPs found in the microwave signal are typical for perturbations of the flare loop by the standing sausage mode of a fast magnetohydrodynamic (MHD) wave. Our analysis indicated that this sausage-oscillating flare loop was the primary source of oscillations in the discussed event. The suggested scenario is that a fundamental sausage harmonic is the dominant cause for the observed QPPs in the microwave emission. The initiation of oscillations in the decimetric emission is caused by the third sausage harmonic via periodic and nonlinear triggering of the acceleration processes in the current sheets, formed at the interface between the sausage-oscillating flare loop and the external coronal loop that extended to higher altitudes. Our results demonstrate the possible role of MHD wave processes in the release and transport of energy during solar flares, linking coherent and incoherent radio emission mechanisms. Title: Analysis of the Eruptive Event after the Solar Flare of June 7, 2011 Authors: Kupryakov, Yu. A.; Gorshkov, A. B.; Kotrč, P.; Kashapova, L. K. Bibcode: 2021ARep...65..876K Altcode: We present the results of the analysis of the observational data for the eruptive event of June 7, 2011 obtained both on spacecraft (SDO, LASCO) and using ground-based solar instruments. The event was characterized by deceleration of the shock front during the first minutes of the evolution from 1150 to 710 km/s. According to the LASCO data, the velocity of the coronal mass ejection (CME) on time scales of more than an hour did not exceed 285 km/s. According to the spectral observations of the ground-based instrument, we found the radial velocities of the fastest features of the exploding prominence to be between 200 and 190 km/s. We paid special attention to studying the physical characteristics of a blob—a separate drop of coronal rain that accompanied the event. The line-of-sight velocity of the blob increased in 5 min from 207 to 263 km/s, its diameter was 5900 km, and the estimated mass was 1.8 × 1012 g; the values of temperature and turbulent velocity of 7880 K and Vturb = 18.7 km/s were obtained,correspondingly. We should note that the finding and measurement of velocities were limited by the capabilities of narrow-band filters and a small wavelength range in most solar instruments. This paper is based on the report made at the conference "Ideas of S.B. Pikelner and S.A. Kaplan and Modern Astrophysics" (Sternberg Astronomical Institute, Moscow State University, February 8-12, 2021). Title: The morphology of average solar flare time profiles from observations of the Sun's lower atmosphere Authors: Kashapova, Larisa K.; Broomhall, Anne-Marie; Larionova, Alena I.; Kupriyanova, Elena G.; Motyk, Ilya D. Bibcode: 2021MNRAS.502.3922K Altcode: 2021MNRAS.tmp..301K; 2021arXiv210202596K We study the decay phase of solar flares in several spectral bands using a method based on that successfully applied to white light flares observed on an M4 dwarf. We selected and processed 102 events detected in the Sun-as-a-star flux obtained with SDO/AIA images in the 1600 and 304 Å channels and 54 events detected in the 1700 Å channel. The main criterion for the selection of time profiles was a slow, continuous flux decay without significant new bursts. The obtained averaged time profiles were fitted with analytical templates, using different time intervals, that consisted of a combination of two independent exponents or a broken power law. The average flare profile observed in the 1700 Å channel decayed more slowly than the average flare profile observed on the M4 dwarf. As the 1700 Å emission is associated with a similar temperature to that usually ascribed to M dwarf flares, this implies that the M dwarf flare emission comes from a more dense layer than solar flare emission in the 1700 Å band. The cooling processes in solar flares were best described by the two exponents model, fitted over the intervals t1 = [0, 0.5]t1/2 and t2 = [3, 10]t1/2, where t1/2 is time taken for the profile to decay to half the maximum value. The broken power-law model provided a good fit to the first decay phase, as it was able to account for the impact of chromospheric plasma evaporation, but it did not successfully fit the second decay phase. Title: Analysis of Properties of SEP Events and their Solar Sources Considering the Magneto- Morphology Classification of Active Regions Authors: Zhukova, A. V.; Kashapova, L. K.; Miteva, R.; Zhdanov, D. A.; Meshalkina, N. S.; Myagkova, I. N. Bibcode: 2020acsp.conf..105Z Altcode: No abstract at ADS Title: The origin of quasi-periodicities during circular ribbon flares Authors: Kashapova, L. K.; Kupriyanova, E. G.; Xu, Z.; Reid, H. A. S.; Kolotkov, D. Y. Bibcode: 2020A&A...642A.195K Altcode: 2020arXiv200802010K Context. Solar flares with a fan-spine magnetic topology are able to form circular ribbons. A previous study based on Hα line observations of the solar flares on 5 March 2014 revealed a uniform and continuous rotation of the magnetic fan-spine. A preliminary analysis of the flare time profiles revealed quasi-periodic pulsations (QPPs) with similar properties in hard X-rays, Hα, and microwaves.
Aims: In this work, we address the question of whether the observed periodicities are related to periodic acceleration of electrons or plasma heating.
Methods: We analysed QPPs in the Hα emission from the centre of the fan (inner ribbon R1), a circular ribbon (R2), a remote source (R3), and an elongated ribbon (R4) located between R2 and R3. We used methods of correlation, Fourier, wavelet, and empirical mode decomposition. We compared the QPPs in Hα emission with those in microwave and X-ray emission.
Results: We found multi-wavelength QPPs with periods around 150 s, 125 s, and 190 s. The 150 s period is seen to co-exist in Hα, hard X-rays, and microwave emissions, which allowed us to connect it with flare kernels R1 and R2. These kernels spatially coincide with the site of the primary flare energy release. The 125 s period is found in the Hα emission of the elongated ribbon R4 and the microwave emission at 5.7 GHz during the decay phase. The 190 s period is present in the emission during all flare phases in the Hα emission of both the remote source, R3, and the elongated ribbon, R4, in soft X-rays and in microwaves at 4-8 GHz.
Conclusions: We connected the dominant 150 s QPPs with the slipping reconnection mechanism occurring in the fan. We suggested that the period of 125 s in the elongated ribbon can be caused by a kink oscillation of the outer spine, connecting the primary reconnection site with the remote footpoint. The period of 190 s is associated with the three-minute sunspot oscillations. Title: Calculation of the intensity of Mg I spectral lines in solar prominences using the Cloudy code model Authors: Kupryakov, Yu. A.; Dodin, A. V.; Schwartz, P.; Kashapova, L. K. Bibcode: 2020A&AT...31..459K Altcode: Spectroscopical observations of several prominences in the MgI lines were carried out from 2014 to 2017. These lines from visible part of the solar spectrum play an important diagnostic role, complementing the UV Mg II resonance lines regularly observed by the IRIS satellite. We found that a rather weak Mg I emission, e.g., in the 5172.6 Å line correlates well with the presence of extended bright areas on the solar disk observed in the 1600 Å SDO / AIA band. However, in many cases the radiation in the 5172.6 Å line is very low, even not detectable, although a bright prominence above the limb or are

on the solar disc were observed. To explain this phenomenon, we have calculated spectra of optically thin plasma using Cloudy code and found that observed ratio of optical lines and UV continuum is possible and the presence of heel processes stimulates luminescence in Mg I and 1600 Å lines. Title: The Calculation of the Intensity of The Mg I Spectral Lines in Solar Prominences Using the Cloudy code Model Authors: Kupryakov, Yu. A.; Dodin, A. V.; Schwartz, P.; Kashapova, L. K. Bibcode: 2019simi.conf..139K Altcode: 2019simi.conf..139D Spectroscopical observations of several prominences in the MgI lines were carried out from 2014 to 2017. These lines from visible part of the solar spectrum play an important diagnostic role, complementing the UV Mg II resonance lines regularly observed by the IRIS satellite. We found that a rather weak Mg I emission, e.g., in the 5172.6 Å line correlates well with the presence of extended bright areas on the solar disk observed in the 1600 Å SDO/AIA band. However, in many cases the radiation in the 5172.6 Å line is very low, even not detectable, although a bright prominence above the limb or flare on the solar disc were observed. To explain this phenomenon, we have calculated spectra of optically thin plasma using Cloudy code and found that observed ratio of optical lines and UV continuum is possible and the presence of heel processes stimulates luminescence in Mg I and 1600 Å lines. Title: Features of Solar Energetic Particle Events During the 23rd Cycle Of Solar Activity and Their Relationship with Solar X-ray, Gamma-Emission and Coronal Mass Ejections Authors: Myagkova, I. N.; Miteva, R.; Kashapova, L.; Bogomolov, A. V.; Danov, D. Bibcode: 2019simi.conf..201M Altcode: The study on the relationship of solar cosmic ray events (in particular, the ratio of the maximum between the proton and electron fluxes) with X-ray and gamma radiation from solar flares, as well as with parameters of coronal mass ejections was carried out. It was done on the basis of SOHO/ERNE proton event catalog (http://newserver.stil.bas.bg/SEPcatalog/) and Solar Flares Catalog based on measurements of X- and gamma-emission (>50 keV) detected by SONG (CORONAS-F – Russian solar observatory) from August, 2001 till December, 2003 (http://swx.sinp.msu.ru/apps/solar_flares_cat/index.php). Solar electron flux (> 300 keV) were measured in the polar caps by MKL-instrument on board CORONAS-F satellite. Title: About Productivity of the Solar Energetic Particle Events Authors: Zhdanov, D. A.; Kashapova, L. K.; Myshyakov, I. I.; Miteva, R. Bibcode: 2019simi.conf..211Z Altcode: We present an analysis of 22 SEPs events related to flares that demonstrate significant microwave emission. We analyzed the microwave burst parameters characterizing acceleration processes for each event. In some events, despite the significant microwave signatures, powerful SEPs were not produced.

The current study aimed to check the correlation of the SEP event productivity of active regions based on features of their magnetic field topology and the presence of type III radio bursts as an additional indicator of open magnetic field lines. The magnetic field during the pre-flare stage was extrapolated by a potential approximation. The obtained results are discussed. Title: Results of work of new spectropolarimeter for solar radio emission observations in the range 50-500 MHz Authors: Muratova, Nataliia; Muratov, Anatoliy; Kashapova, Larisa Bibcode: 2019STP.....5c...3M Altcode: 2019SZF.....5c...3M Ground-based observations within meter radio range are of importance for understanding processes occurring in the solar corona. We present concepts, block diagram, and results of first observations of the Solar Spectropolarimeter of Meter Range (SSMD), launched for solar observations in the range 50-500 MHz in April 2016. The main purpose of this work was to develop an up-to-date digital radio spectropolarimeter able to record the full Stokes vector for sporadic solar phenomena taking place in the 50-500 MHz range. We use a crossed log periodic antenna to detect solar radio emission. This antenna can simultaneously obtain horizontal and vertical polarization components. The main part of SSMD is a digital receiver based on an FX correlator architecture. We use the Fast Fourier Transform (FFT) algorithm based on the real-time pipeline circuit to construct amplitude dynamic spectra (intensity vs frequency and time). SSMD has 4608 frequency channels with 97.66 kHz channel bandwidth and 97.66 kHz spacing. Time resolution is 1 s. The spectropolarimeter has a 50-500 MHz range. It can record the full Stokes vector. At present, SSMD observes two of four parameters in regular mode (I and V). We have observational data since 2016. The catalog development is in progress. We plan to improve time and frequency characteristics, record all Stokes parameters, and conduct a calibration. We are working on providing access to the data archive via the Internet. Title: Study on the Features of the SEP Solar Origin Based on Microwave Observations Authors: Kashapova, L. K.; Meshalkina, N. S.; Miteva, R.; Zhukova, A. V.; Myagkova, I. N. Bibcode: 2019simi.conf..185K Altcode: We present the results on the analysis of microwave (MW) emission in solar flares related to strong solar energetic particle (SEP) events observed during the 23rd solar cycle. The parameters of the MW spectrum were used as indicators of acceleration processes during solar flares. The magnetic topology of the active regions (ARs) that produced the flares were taken into account by the approach suggested by Abrameko et al. [2018]. We found that during their evolution most of the ARs related to proton-rich SEP events violated at least one of the classical sunspot group evolution laws (Hale's law, Joy's law et cetera). However, the statistical study of all ARs of the cycle revealed the domination of normal ARs. The dependences between SEP events and MW indicators of the acceleration process for different groups are studied and discussed. Title: Parameters of Thermal and Non-thermal X-ray and Gamma Ray Emission of Solar Flares, Observed onboard CORONAS-F Authors: Bogomolov, A. V.; Myagkova, I. N.; Miteva, R.; Danov, D.; Kashapova, L. K. Bibcode: 2019simi.conf..179B Altcode: Based on data from the SPR-N and SONG multi-channel hard electromagnetic radiation detectors onboard the CORONAS-F space observatory and the X-ray monitors onboard GOES satellites, we have distinguished the thermal and non-thermal components in the X-ray spectrum of a number of powerful flares of 23rd solar activity cycle. Temporal, spectral and energetic parameters of the flares were analyzed using the catalogs of Solar Energetic Particles and Related Phenomena (http://newserver.stil.bas.bg/SEPcatalog/). Title: Quasi-periodic pulsations in a solar flare with an unusual phase shift Authors: Kupriyanova, Elena G.; Kashapova, Larisa K.; Van Doorsselaere, Tom; Chowdhury, Partha; Srivastava, Abhishek K.; Moon, Yong-Jae Bibcode: 2019MNRAS.483.5499K Altcode: 2018arXiv181209868K; 2018MNRAS.tmp.3312K Two kinds of processes could occur during the flare decay phase: processes of energy release or processes of energy relaxation. Quasi-periodic pulsations (QPPs) of the broad-band emission are a good tool for the verification of mechanisms. We aim to study the processes during the decay phase of the X-class solar flare SOL2014-03-29T17:48. The observations in X-ray, microwave, and extreme ultraviolet bands are exploited to study the fine temporal, spatial, and spectral structures of the flare. The periods, amplitudes, and phases of both the fluxes and physical parameters [emission measure (EM), temperature] are studied using standard methods of correlation, Fourier, and wavelet analyses. It is found that the source of the QPPs is associated with the uniform post-flare loop. The X-ray source is located at the top of the arcade. QPPs with the similar characteristic time scales of P ≈ 74-80 s are found in the X-ray (3-25 keV) and microwave (15.7 GHz) emissions. Besides, QPPs with the same period are found in the time profiles of both the temperature (Te) and EM. The QPPs in temperature and the QPPs in EM demonstrate antiphase behaviour. The analysis reveals the quasi-periodic process of energy relaxation, without any additional source of energy during the decay phase. The periods of the QPPs are in a good agreement with second harmonic of standing slow magneto-acoustic wave in the arcade that could be triggered by a Moreton wave initiated by the flare in the direct vicinity of the arcade. Title: Onset Time of the GLE 72 Observed at Neutron Monitors and its Relation to Electromagnetic Emissions Authors: Kurt, V.; Belov, A.; Kudela, K.; Mavromichalaki, H.; Kashapova, L.; Yushkov, B.; Sgouropoulos, C. Bibcode: 2019SoPh..294...22K Altcode: We present an overview of the ground-level enhancement (GLE 72) of the cosmic-ray intensity associated with the recent powerful solar flare SOL2017-09-10 (X-ray class X8.9) based on the available neutron monitor (NM) network observations and on data from the satellite GOES 13. The maximum increase at high-latitude near-sea-level NMs was ≈6 -7 % (2-min averages), greater with better time resolution. A scatter plot of the maximum increase of the GLE versus solar energetic-particle (SEP, proton) flux >100 MeV shows one of the softest spectra among GLEs relative to the SEP fluxes. However, at two high-mountain middle-latitude NMs the increase was ≈1 % , indicating the possibility of proton acceleration up to 6 GeV. Among the analyzed NM data the Fort Smith (FSMT) NM shows the earliest and the rather high increase between 16:06 - 16:08 UT. This indicates an anisotropy in the first phase of the GLE event. We calculate the acceptance cones of several NM stations at high latitudes and contours of pitch angles corresponding to the interplanetary magnetic field (IMF). When employing the available data we find that pion-decay γ -ray emission onset is in accordance with the time of the main flare energy release. The observed time interval of the impulsive burst of >100 MeVγ -ray emission probably corresponds to the time of a turbulent current sheet creation. The observed location of the impulsive burst pion-decay emission source coincides with the active region and the cusp-shaped structure. It seems that models assuming sub-relativistic proton production beginning in a turbulent reconnecting current sheet are consistent with the observations. If these particles were released from the Sun during a type III emission with a pion-decay maximum at 16 :00 :30 ±30 UT, we get a plausible path length equal to 1.5 ±0.3 AU of the particles responsible for the onset of the SEP event and GLE. The time lag of GLE 72 corresponds to the most probable interval of the time difference between GLE onset and main flare energy release. Although other scenarios are not excluded we attribute the protons that create the pion-decay emission and the protons responsible for the GLE and SEP event onset to a general population of accelerated particles. Title: On the role of preflares in tornado-type prominences Authors: Kupryakov, Yu. A.; Kotrc, P.; Kashapova, L. K. Bibcode: 2019A&AT...31..177K Altcode: We present first results of a study of rotation parameters of the tornado-type promi- nences using Hα line spectra and filtergrams. The prominences of the tornado-type were observed by ground-based spectrographs MFS and HSFA 2 in the Ondrejov Observatory (Astronomical Institute of AS CR) from 2000 to 2017. The analysis took into account the structure and dynamics of selected prominences and a comparison of the data of Hα with the EUV observations of SDO (304 Å, 193 Å, 171 Å), as well as information about the emission of flares in the X-ray range. We found that most of the analyzed events were associated with solar flares of classes from B5 to M5 by GOES classification. We revealed two types of motions in the prominences. The first type shows the Doppler velocity quasi-symmetry of the values in the "blue" and "red" Hα line wings. The events of the other type demonstrate a difference of up to one order of velocities in the direction of, and towards, the observer. Title: Characteristics of SEP Events and Their Solar Origin During the Evolution of Active Region NOAA 10069 Authors: Kashapova, L. K.; Miteva, R.; Myagkova, I. N.; Bogomolov, A. V. Bibcode: 2019SoPh..294....9K Altcode: We present the results of a comparative analysis of the properties of a series of successive solar flares, which occurred in active region (AR) 10069 in August 2002, and the associated solar energetic particle (SEP) events. The active region was extremely flare productive during its evolution. The solar flare characteristics are based on X-ray and radio emission data: maximum detected photon energies and spectral index, delays between microwave, metric-radio and, hard X-ray emissions. The coronal mass ejections (CMEs) are characterized by their projected speed. The SEP properties are described by the relative electron to proton abundance as well as by the abundance of lower relative to higher energy particles. The analysis carried out supports some previous results obtained by large statistical studies, but at the same time refutes others. For example, the set of analyzed events that occurred in the AR did not show clear evidence of the big flare syndrome though the large proton events observed near Earth were always accompanied by CMEs. Some of the peculiar observations could be the result of the magnetic topology of the AR. Title: Comparative analysis of the proton generation efficiency during 17 March 2003 and 11 April 2004 solar flares Authors: Bogomolov, A. V.; Myagkova, I. N.; Myshyakov, I.; Tsvetkov, Ts; Kashapova, L.; Miteva, R. Bibcode: 2018JASTP.179..517B Altcode: We present the comparative analysis of the solar energetic particle (SEP) event properties and the indicators of acceleration processes in solar flares - the hard X-rays (HXR) and radio emission from microwaves to the meter-range. We focus our study on the two SEP events associated with solar flares with similar characteristics in HXR emission and the close location on solar disk. The proton flux in the SEP event associated with the weaker flare by GOES class in soft X-ray (SXR) (C9.6/SOL2004-Apr-11) was more than an order higher than in the SEP event associated with the more powerful solar flare (X1.5/SOL2003-Mar-17). At the same time, the electron fluxes in both SEP events were comparable. Both flares were followed by CMEs with speed above 1000 km s-1. The analysis of SEP fluxes and flare plasma parameters was done taking into account the magnetic topology of the active region (AR) and its evolution before and during the solar flares. The 3D reconstruction of the potential magnetic field showed the existence of an arcade of high loops covering the active region where the more powerful flare occurred. The flare associated with the proton-rich SEP event occurred in the active region where 3D reconstruction revealed a fan of high loops associated with open magnetic field lines. We suppose that the arcade of high loops could be the factor which prevents an escape of the accelerated particles into the interplanetary space (IPS) while the fan of high loops facilitates the production of the more proton-rich SEP events. Results of the analysis show a necessity to use topology of ARs as a parameter in statistical studies of SEP event origins. Title: Radio, Hard X-Ray, and Gamma-Ray Emissions Associated with a Far-Side Solar Event Authors: Grechnev, V. V.; Kiselev, V. I.; Kashapova, L. K.; Kochanov, A. A.; Zimovets, I. V.; Uralov, A. M.; Nizamov, B. A.; Grigorieva, I. Y.; Golovin, D. V.; Litvak, M. L.; Mitrofanov, I. G.; Sanin, A. B. Bibcode: 2018SoPh..293..133G Altcode: 2018arXiv180810103G The far-side solar eruptive event SOL2014-09-01 produced hard electromagnetic and radio emissions that were observed with detectors at near-Earth vantage points. Especially challenging was a long-duration > 100 MeV γ -ray burst that was probably produced by accelerated protons exceeding 300 MeV. This observation raised the question how high-energy protons could reach the Earth-facing solar surface. Some preceding studies discussed a scenario in which protons accelerated by a shock driven by a coronal mass ejection high in the corona return to the solar surface. We continue with the analysis of this challenging event, involving radio images from the Nançay Radioheliograph and hard X-ray data from the High Energy Neutron Detector (HEND) of the Gamma-Ray Spectrometer onboard the Mars Odyssey space observatory located near Mars. HEND recorded unocculted flare emission. The results indicate that the emissions observed from the Earth's direction were generated by flare-accelerated electrons and protons trapped in static long coronal loops. They can be reaccelerated in these loops by a shock wave that was excited by the eruption, being initially not driven by a coronal mass ejection. The results highlight ways to address the remaining questions. Title: Multi-instrument view on solar eruptive events observed with the Siberian Radioheliograph: From detection of small jets up to development of a shock wave and CME Authors: Grechnev, V. V.; Lesovoi, S. V.; Kochanov, A. A.; Uralov, A. M.; Altyntsev, A. T.; Gubin, A. V.; Zhdanov, D. A.; Ivanov, E. F.; Smolkov, G. Ya.; Kashapova, L. K. Bibcode: 2018JASTP.174...46G Altcode: 2018arXiv180502564G The first 48-antenna stage of the Siberian Radioheliograph (SRH) started single-frequency test observations early in 2016, and since August 2016 it routinely observes the Sun at several frequencies in the 4-8 GHz range with an angular resolution of 1-2 arc minutes and an imaging interval of about 12 s. With limited opportunities of the incomplete antenna configuration, a high sensitivity of about 100 Jy allows the SRH to contribute to the studies of eruptive phenomena along three lines. First, some eruptions are directly visible in SRH images. Second, some small eruptions are detectable even without a detailed imaging information from microwave depressions caused by screening the background emission by cool erupted plasma. Third, SRH observations reveal new aspects of some events to be studied with different instruments. We focus on an eruptive C2.2 flare on 16 March 2016 around 06:40, one of the first flares observed by the SRH. Proceeding from SRH observations, we analyze this event using extreme-ultraviolet, hard X-ray, white-light, and metric radio data. An eruptive prominence expanded, brightened, and twisted, which indicates a time-extended process of the flux-rope formation together with the development of a large coronal mass ejection (CME). The observations rule out a passive role of the prominence in the CME formation. The abrupt prominence eruption impulsively excited a blast-wave-like shock, which appeared during the microwave burst and was manifested in an "EUV wave" and Type II radio burst. The shock wave decayed and did not transform into a bow shock because of the low speed of the CME. Nevertheless, this event produced a clear proton enhancement near Earth. Comparison with our previous studies of several events confirms that the impulsive-piston shock-excitation scenario is typical of various events. Title: Results of comparative analysis of the SEP events and the microwave bursts observed by 2-24 GHz and 4-8 GHz spectropolarimeters in 2010-2016 Authors: Zhdanov, D.; Kashapova, L. K.; Miteva, R. Bibcode: 2018simi.conf..105Z Altcode: We present a relationship analysis between the solar energetic particle (SEP) events and the microwave (MW) spectral observations of the solar bursts detected in 2010-2016. The information about the SEP events is taken from the Wind/EPACT catalog based on data in the period 1996-2016. We use MW data from the archive of MW observations in the range 2-24 GHz. Observations were made by spectropolarimeters of the SSRT observatory (Russia). We found that 40 events are present in both catalogs. We tested the relationships between the proton spectral index of SEP events and the peak frequency of the MW bursts and presence of circular polarization in MW emission of selected events. The results are finally discussed. Title: Analysing of the SEP origins based on microwave emission of solar flares Authors: Kashapova, L.; Mehsalkina, N.; Miteva, R.; Myagkova, I.; Bogomolov, A. Bibcode: 2018simi.conf..119K Altcode: We present the results on the analysis of microwave emission in solar flares related to strong solar energetic particle (SEP) events observed during the previous solar cycle. The target of the work is to find criteria based on the solar flare features that would allow us to separate the SEP events into groups with more homogeneous physical/topological properties. In the current study, we compared peak frequency of microwave spectra and spectral index with spectral characteristics of SEP proton fluxes. The two groups of events related to the value of the peak frequency are found. We discuss revealed tendencies and physical reasons of the two population appearances. Title: The efficiency of solar energetic particle generation: CORONAS-F mission data analysis Authors: Myagkova, I. N.; Miteva, R.; Kashapova, L.; Bogomolov, A. V.; Petrov, V.; Tsvetkov, Ts.; Meshalkina, N.; Myshyakov, I. Bibcode: 2018simi.conf..114M Altcode: We present the results of a comparative analysis on the efficiency of the solar energetic particle events (SEP) and related solar flares. Both SEP events and solar flares were detected by the CORONAS-F solar mission. We selected the SEP events based on the presence of simultaneous observations from the hard X-ray (HXR) instrument SONG (CORONAS-F satellite) with radio emission ranging from microwaves to the meter-range, as evidence of accelerated particles generated during the events and solar proton and electron data measured by MKL instrument on board CORONAS-F satellite in polar caps. The results are discussed from point of using solar flare emission features as the criteria of generation of SEP event with high proton abundance. Title: Homologous Circular-ribbon Flares Driven by Twisted Flux Emergence Authors: Xu, Z.; Yang, K.; Guo, Y.; Zhao, J.; Zhao, Z. J.; Kashapova, L. Bibcode: 2017ApJ...851...30X Altcode: In this paper, we report two homologous circular-ribbon flares associated with two filament eruptions. They were well observed by the New Vacuum Solar Telescope and the Solar Dynamics Observatory on 2014 March 5. Prior to the flare, two small-scale filaments enclosed by a circular pre-flare brightening lie along the circular polarity inversion line around the parasitic polarity, which has shown a continuous rotation since its first appearance. Two filaments eventually erupt in sequence associated with two homologous circular-ribbon flares and display an apparent writhing signature. Supplemented by the nonlinear force-free field extrapolation and the magnetic field squashing factor investigation, the following are revealed. (1) This event involves the emergence of magnetic flux ropes into a pre-existing polarity area, which yields the formation of a 3D null-point topology in the corona. (2) Continuous input of the free energy in the form of a flux rope from beneath the photosphere may drive a breakout-type reconnection occurring high in the corona, supported by the pre-flare brightening. (3) This initiation reconnection could release the constraint on the flux rope and trigger the MHD instability to first make filament F1 lose equilibrium. The subsequent more violent magnetic reconnection with the overlying flux is driven during the filament rising. In return, the eruption of filament F2 is further facilitated by the reduction of the magnetic tension force above. These two processes form a positive feedback to each other to cause the energetic mass eruption and flare. Title: The origin of SEP events: New research collaboration and network on space weather Authors: Miteva, Rositsa; Kashapova, Larisa; Myagkova, Irina; Meshalkina, Nataliia; Petrov, Nikola; Bogomolov, Andrey; Myshyakov, Ivan; Tsvetkov, Tsvetan; Danov, Dimitar; Zdanov, Dmitriy Bibcode: 2017ses..conf...57M Altcode: A new project on the solar energetic particles (SEPs) and their solar origins (flares and coronal mass ejections) is described here. The main aim of this project is to answer the question - whether the SEPs observed in situ are driven by flares, by CMEs or both accelerators contribute to an extent which varies from event to event - by deducing a quantitative measure of the flare vs. CME contribution, duration and efficiency. New observations (SONG/Koronas-F, Relec/Vernov) and new approaches of analysis will be utilized (e.g., magnetic topology of active regions using 3D extrapolation techniques of detailed case studies together with statistical analysis of the phenomena). In addition, the identification of the uncertainty limits of SEP injection, onset time and testing the validity of assumptions often taken for granted (association procedures, solar activity longitudinal effects, correlation analysis, etc.) are planned. The project outcomes have the capacity to contribute to other research fields for improvement of modeling schemes and forecasting methods of space weather events. Title: CORONAS-F observation of gamma-ray emission from the solar flare on 2003 October 29 Authors: Kurt, Victoria G.; Yushkov, Boris Yu.; Galkin, Vladimir I.; Kudela, Karel; Kashapova, Larisa K. Bibcode: 2017NewA...56..102K Altcode: 2018arXiv180802627K Appreciable hard X-ray (HXR) and gamma-ray emissions in the 0.04-150 MeV energy range associated with the 2003 October 29 solar flare (X10/3B) were observed at 20:38-20:58 UT by the SONG instrument onboard the CORONAS-F mission. To restore flare gamma-ray spectra we fitted the SONG energy loss spectra with a three-component model of the incident spectrum: (1) a power law in energy, assumed to be due to electron bremsstrahlung; (2) a broad continuum produced by prompt nuclear de-excitation gamma-lines; and (3) a broad gamma-line generated from pion-decay. We also restored spectra from the RHESSI data, compared them with the SONG spectra and found a reasonable agreement between these spectra in the 0.1-10 MeV energy range. The pion-decay emission was observed from 20:44:20 UT and had its maximum at 20:48-20:51 UT. The power-law spectral index of accelerated protons estimated from the ratio between intensities of different components of gamma rays changed with time. The hardest spectrum with a power-law index S = -3.5 - 3.6 was observed at 20:48-20:51 UT. Time histories of the pion-decay emission and proton spectrum were compared with changes of the locations of flare energy release as shown by RHESSI hard X-ray images and remote and remote Hα brightenings. An apparent temporal correlation between processes of particle acceleration and restructuring of flare magnetic field was found. In particular, the protons were accelerated to subrelativistic energies after radical change of the character of footpoint motion from a converging motion to a separation motion. Title: Siberian Radioheliograph: first results Authors: Lesovoi, Sergey; Altyntsev, Alexander; Kochanov, Aleksey; Grechnev, Victor; Gubin, Aleksey; Zhdanov, Dmitriy; Ivanov, Evgeniy; Uralov, Arkadiy; Kashapova, Larisa; Kuznetsov, Aleksey; Meshalkina, Nataliya; Sych, Robert Bibcode: 2017STP.....3a...3L Altcode: 2017SZF.....3a...3L; 2017arXiv170407100L Regular observations of active processes in the solar atmosphere have been started using the first stage of the multiwave Siberian Radioheliograph (SRH), a T-shaped 48-antenna array with a 4-8 GHz operating frequency range and a 10 MHz instantaneous receiving band. Antennas are mounted on the central antenna posts of the Siberian Solar Radio Telescope. The maximum baseline is 107.4 m, and the angular resolution is up to 70". We present examples of observations of the solar disk at different frequencies, "negative" bursts, and solar flares. The sensitivity to compact sources reaches 0.01 solar flux units (≈10-4 of the total solar flux) with an accumulation time of about 0.3 s. The high sensitivity of SRH enables monitoring of solar activity and allows studying active processes from characteristics of their microwave emission, including faint events, which could not be detected previously. Title: Fermi-LAT Observations of High-energy Behind-the-limb Solar Flares Authors: Ackermann, M.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonino, R.; Bottacini, E.; Bregeon, J.; Bruel, P.; Buehler, R.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Cecchi, C.; Charles, E.; Ciprini, S.; Costanza, F.; Cutini, S.; D'Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Drell, P. S.; Favuzzi, C.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Giroletti, M.; Grenier, I. A.; Guillemot, L.; Guiriec, S.; Jogler, T.; Jóhannesson, G.; Kashapova, L.; Krucker, S.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Liu, W.; Longo, F.; Loparco, F.; Lubrano, P.; Magill, J. D.; Maldera, S.; Manfreda, A.; Mazziotta, M. N.; Mitthumsiri, W.; Mizuno, T.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Pal'shin, V.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Petrosian, V.; Piron, F.; Principe, G.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, O.; Rubio da Costa, F.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Tajima, H.; Thayer, J. B.; Torres, D. F.; Troja, E.; Vianello, G. Bibcode: 2017ApJ...835..219A Altcode: 2017arXiv170200577A We report on the Fermi-LAT detection of high-energy emission from the behind-the-limb (BTL) solar flares that occurred on 2013 October 11, and 2014 January 6 and September 1. The Fermi-LAT observations are associated with flares from active regions originating behind both the eastern and western limbs, as determined by STEREO. All three flares are associated with very fast coronal mass ejections (CMEs) and strong solar energetic particle events. We present updated localizations of the >100 MeV photon emission, hard X-ray (HXR) and EUV images, and broadband spectra from 10 keV to 10 GeV, as well as microwave spectra. We also provide a comparison of the BTL flares detected by Fermi-LAT with three on-disk flares and present a study of some of the significant quantities of these flares as an attempt to better understand the acceleration mechanisms at work during these occulted flares. We interpret the HXR emission to be due to electron bremsstrahlung from a coronal thin-target loop top with the accelerated electron spectra steepening at semirelativistic energies. The >100 MeV gamma-rays are best described by a pion-decay model resulting from the interaction of protons (and other ions) in a thick-target photospheric source. The protons are believed to have been accelerated (to energies >10 GeV) in the CME environment and precipitate down to the photosphere from the downstream side of the CME shock and landed on the front side of the Sun, away from the original flare site and the HXR emission. Title: Fermi Large Area Telescope Observations of High-Energy Gamma-ray Emission From Behind-the-limb Solar Flares Authors: Omodei, Nicola; Pesce-Rollins, Melissa; Petrosian, Vahe; Liu, Wei; Rubio da Costa, Fatima; Golenetskii, Sergei; Kashapova, Larisa; Krucker, Sam; Palshin, Valentin; Fermi Large Area Telescope Collaboration Bibcode: 2017APS..APR.Y3005O Altcode: Fermi LAT >30 MeV observations of the active Sun have increased the number of detected solar flares by almost a factor of 10 with respect to previous space observations. Of particular interest are the recent detections of three solar flares whose position behind the limb was confirmed by the STEREO-B spacecraft. These observations sample flares from active regions originating from behind both the eastern and western limbs and include an event associated with the second ground level enhancement event (GLE) of the 24th Solar Cycle. While gamma-ray emission up to tens of MeV resulting from proton interactions has been detected before from occulted solar flares, the significance of these particular events lies in the fact that these are the first detections of >100 MeV gamma-ray emission from footpoint-occulted flares. These detections present an unique opportunity to diagnose the mechanisms of high-energy emission and particle acceleration and transport in solar flares. We will present the Fermi-LAT, RHESSI and STEREO observations of these flares and discuss the various emission scenarios for these sources. Title: Solar X-ray Emission Measured by the Vernov Mission During September - October of 2014 Authors: Myagkova, I. N.; Bogomolov, A. V.; Kashapova, L. K.; Bogomolov, V. V.; Svertilov, S. I.; Panasyuk, M. I.; Kuznetsova, E. A.; Rozhkov, G. V. Bibcode: 2016SoPh..291.3439M Altcode: 2016SoPh..tmp..128M Solar hard X-ray and γ -ray emissions were measured by the Detector of the Roentgen and Gamma-ray Emissions (DRGE) instrument, which is part of the RELEC set of instruments operated onboard the Russian satellite Vernov, from July 8, 2014 until December 10, 2014 (on a solar-synchronous orbit with an apogee of 830 km, perigee of 640 km, and an inclination of 98.4). RELEC measurements of 18 flares with X-ray energy >30 keV, taken in September - October 2014, were connected with the same active region with the number AR 12172 during the first rotation and AR 12192 during the next one. These measurements were compared to the data obtained with RHESSI, Konus-Wind, Fermi Observatory, Radio Solar Telescope Net (RSTN), and the Nobeyama Radioheliograph (NoRH) operating at the same time. Quasi-periodicities with similar periods of 7 ±2 s were found in about one third of all flares measured by RELEC (Vernov) from September 24 until October 30, 2014. Title: Relationship of Type III Radio Bursts with Quasi-periodic Pulsations in a Solar Flare Authors: Kupriyanova, E. G.; Kashapova, L. K.; Reid, H. A. S.; Myagkova, I. N. Bibcode: 2016SoPh..291.3427K Altcode: 2016arXiv160800129K; 2016SoPh..tmp..127K We studied a solar flare with pronounced quasi-periodic pulsations detected in the microwave, X-ray, and radio bands. We used correlation, Fourier, and wavelet analyses methods to examine the temporal fine structures and relationships between the time profiles in each wave band. We found that the time profiles of the microwaves, hard X-rays, and type III radio bursts vary quasi-periodically with a common period of 40 - 50 s. The average amplitude of the variations is high, above 30 % of the background flux level, and reaches 80 % after the flare maximum. We did not find this periodicity in either the thermal X-ray flux component or in the source size dynamics. Our findings indicate that the detected periodicity is probably associated with periodic dynamics in the injection of non-thermal electrons, which can be produced by periodic modulation of magnetic reconnection. Title: Diagnosing the Source Region of a Solar Burst on 26 September 2011 by Using Microwave Type-III Pairs Authors: Tan, B. L.; Karlický, M.; Mészárosová, H.; Kashapova, L.; Huang, J.; Yan, Y.; Kontar, E. P. Bibcode: 2016SoPh..291.2407T Altcode: 2016SoPh..tmp..143T; 2016arXiv160605410T We report a peculiar and interesting train of microwave Type-III pair bursts in the impulsive rising phase of a solar flare on 26 September 2011. The observations include radio spectrometers at frequencies of 0.80 - 2.00 GHz from the Ondřejov radiospectrograph in the Czech Republic (ORSC), hard X-ray from the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) and Gamma-Ray Burst Monitor onboard the Fermi Space Telescope (Fermi/GRB), EUV images from the Sun Watcher using APS detectors and image Processing instrument onboard the Project for Onboard Autonomy 2 (SWAP/PROBA2), and magnetograms from the Helioseismic and Magnetic Imager onboard the Solar Dynamic Observatory (SDO/HMI). By using a recently developed method (Tan et al., Res. Astron. Astrophys.16, 82, 2016a), we diagnosed the plasma density, temperature, plasma-β , magnetic field near the source region, the energy of energetic electrons, and the distance between the acceleration region and the emission start sites of Type-III bursts. From the diagnostics, we find that i) The plasma density, temperature, magnetic field, and the distance between the acceleration region and the emission start sites have almost no obvious variations during the period of Type-III pair trains, while the energy of electrons has an obvious peak value that is consistent with the hard X-ray emission. ii) The plasma-β is much higher than unity, showing a highly dynamic process near the emission start site of Type-III bursts. iii) Although the reversed-slope Type-III branches drift more slowly by one order of magnitude than that of the normal Type-IIIs, the related descending and ascending electrons still could have energy of the same order of magnitude. These facts indicate that both the ascending and descending electrons are possibly accelerated by a similar mechanism and in a small source region. These diagnostics can help us to understand the physics in the source region of solar bursts. Title: Broadband microwave sub-second pulsations in an expanding coronal loop of the 2011 August 10 flare Authors: Mészárosová, H.; Rybák, J.; Kashapova, L.; Gömöry, P.; Tokhchukova, S.; Myshyakov, I. Bibcode: 2016A&A...593A..80M Altcode: 2016arXiv160904217M
Aims: We studied the characteristic physical properties and behavior of broadband microwave sub-second pulsations observed in an expanding coronal loop during the GOES C2.4 solar flare on 2011 August 10.
Methods: The complex microwave dynamic spectrum and the expanding loop images were analyzed with the help of SDO/AIA/HMI, RHESSI, and the STEREO/SECCHI-EUVI data processing software, wavelet analysis methods, the GX Simulator tool, and the NAFE method.
Results: We found sub-second pulsations and other different burst groups in the complex radio spectrum. The broadband (bandwidth about 1 GHz) sub-second pulsations (temporal period range 0.07-1.49 s, no characteristic dominant period) lasted 70 s in the frequency range 4-7 GHz. These pulsations were not correlated at their individual frequencies, had no measurable frequency drift, and zero polarization. In these pulsations, we found the signatures of fast sausage magnetoacoustic waves with the characteristic periods of 0.7 and 2 s. The other radio bursts showed their characteristic frequency drifts in the range of -262-520 MHz s-1. They helped us to derive average values of 20-80 G for the coronal magnetic field strength in the place of radio emission. It was revealed that the microwave event belongs to an expanding coronal loop with twisted sub-structures observed in the 131, 94, and 193 Å SDO/AIA channels. Their slit-time diagrams were compared with the location of the radio source at 5.7 GHz to realize that the EUV intensity of the expanding loop increased just before the radio source triggering. We reveal two EUV bidirectional flows that are linked with the start time of the loop expansion. Their positions were close to the radio source and propagated with velocities within a range of 30-117 km s-1.
Conclusions: We demonstrate that periodic regime of the electron acceleration in a model of the quasi-periodic magnetic reconnection might be able to explain physical properties and behavior of the sub-second pulsations. The depolarization process of the microwave emission might be caused by a plasma turbulence in the radio source. Finally, the observed EUV flows might be linked with reconnection outflows. Title: Time delays in the nonthermal radiation of solar flares according to observations of the CORONAS-F satellite Authors: Tsap, Yu. T.; Stepanov, A. V.; Kashapova, L. K.; Myagkova, I. N.; Bogomolov, A. V.; Kopylova, Yu. G.; Goldvarg, T. B. Bibcode: 2016CosRe..54..285T Altcode: In 2001-2003, the X-ray and microwave observations of ten solar flares of M- and X-classes were carried out by the CORONAS-F orbital station, the RSTN Sun service, and Nobeyama radio polarimeters. Based on these observations, a correlation analysis of time profiles of nonthermal radiation was performed. On average, hard X-ray radiation outstrips the microwave radiation in 9 events, i.e., time delays are positive. The appearance of negative delays is associated with effective scattering of accelerated electrons in pitch angles, where the length of the free path of a particle is less than the half-length of a flare loop. The additional indications are obtained in favor of the need to account for the effect of magnetic mirrors on the dynamics of energetic particles in the coronal arches. Title: A Cold Flare with Delayed Heating Authors: Fleishman, Gregory D.; Pal'shin, Valentin D.; Meshalkina, Natalia; Lysenko, Alexandra L.; Kashapova, Larisa K.; Altyntsev, Alexander T. Bibcode: 2016ApJ...822...71F Altcode: 2016arXiv160307273F Recently, a number of peculiar flares have been reported that demonstrate significant nonthermal particle signatures with low, if any, thermal emission, which implies a close association of the observed emission with the primary energy release/electron acceleration region. This paper presents a flare that appears “cold” at the impulsive phase, while displaying delayed heating later on. Using hard X-ray data from Konus-Wind, microwave observations by SSRT, RSTN, NoRH, and NoRP, context observations, and three-dimensional modeling, we study the energy release, particle acceleration, and transport, and the relationships between the nonthermal and thermal signatures. The flaring process is found to involve the interaction between a small loop and a big loop with the accelerated particles divided roughly equally between them. Precipitation of the electrons from the small loop produced only a weak thermal response because the loop volume was small, while the electrons trapped in the big loop lost most of their energy in the coronal part of the loop, which resulted in coronal plasma heating but no or only weak chromospheric evaporation, and thus unusually weak soft X-ray emission. The energy losses of the fast electrons in the big tenuous loop were slow, which resulted in the observed delay of the plasma heating. We determined that the impulsively accelerated electron population had a beamed angular distribution in the direction of the electric force along the magnetic field of the small loop. The accelerated particle transport in the big loop was primarily mediated by turbulent waves, which is similar to other reported cold flares. Title: A Tiny Eruptive Filament as a Flux-Rope Progenitor and Driver of a Large-Scale CME and Wave Authors: Grechnev, V. V.; Uralov, A. M.; Kochanov, A. A.; Kuzmenko, I. V.; Prosovetsky, D. V.; Egorov, Y. I.; Fainshtein, V. G.; Kashapova, L. K. Bibcode: 2016SoPh..291.1173G Altcode: 2016SoPh..tmp...57G; 2016arXiv160400800G A solar eruptive event SOL2010-06-13 observed with the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) has been extensively discussed in the contexts of the CME development and an associated extreme-ultraviolet (EUV) wave-like transient in terms of a shock driven by the apparent CME rim. Continuing the analysis of this event, we have revealed an erupting flux rope, studied its properties, and detected wave signatures inside the developing CME. These findings have allowed us to establish new features in the genesis of the CME and associated EUV wave and to reconcile all of the episodes into a single causally related sequence. i) A hot 11 MK flux rope developed from the structures initially associated with a compact filament system. The flux rope expanded with an acceleration of up to 3 km s−2 one minute before a hard X-ray burst and earlier than any other structures, reached a velocity of 420 km s−1, and then decelerated to about 50 km s−1. ii) The CME development was driven by the expanding flux rope. Closed coronal structures above the rope got sequentially involved in the expansion from below upwards, came closer together, and apparently disappeared to reveal their common envelope, the visible rim, which became the outer boundary of the cavity. The rim was probably associated with the separatrix surface of a magnetic domain, which contained the pre-eruptive filament. iii) The rim formation was associated with a successive compression of the upper active-region structures into the CME frontal structure (FS). When the rim was formed, it resembled a piston. iv) The disturbance responsible for the consecutive CME formation episodes was excited by the flux rope inside the rim, and then propagated outward. EUV structures arranged at different heights started to accelerate, when their trajectories in the distance-time diagram were crossed by that of the fast front of this disturbance. v) Outside the rim and FS, the disturbance propagated like a blast wave, manifesting in a type II radio burst and a leading part of the EUV transient. Its main, trailing part was the FS, which consisted of swept-up 2 MK coronal loops enveloping the expanding rim. The wave decelerated and decayed into a weak disturbance soon afterwards, being not driven by the trailing piston, which slowed down. Title: Sunspot waves and flare energy release Authors: Sych, R.; Karlický, M.; Altyntsev, A.; Dudík, J.; Kashapova, L. Bibcode: 2015A&A...577A..43S Altcode: 2014arXiv1409.2947S Context. We study the possibility of flare process triggering by waves propagating from the sunspot along a magnetic loop (channel) to a nearby flare site.
Aims: We present a relationship between the dynamics of ~3-min slow magnetoacoustic waves in the sunspot and flare emergence process. Waves propagating in the magnetic channel whose one foot is anchored in the umbra represent the disturbing agent responsible for triggering the flare energy release.
Methods: We applied time-distance plots and pixel wavelet filtration methods to obtain spatio-temporal distribution of wave power variations in radio and SDO/AIA data. To find the magnetic channel, we used potential magnetic field extrapolation of SDO/HMI magnetograms. The propagation velocity of wave fronts was measured from wave locations at specific times.
Results: In the correlation curves of the 17 GHz (NoRH) radio emission, we found a monotonous energy amplification of the 3-min waves in the sunspot umbra before the 2012 June 7 flare. This amplification was associated with an increase in the length of the oscillatory wakes in coronal loops (SDO/AIA, 171 Å) prior to the flare onset. A peculiarity of the flare is the constant level of the flare emission in soft X-rays (RHESSI, 3-25 keV) for ~10 min after the short impulsive phase, which indicates continuing energy release. Throughout this time, we found transverse oscillations of the flare loop with a 30 s period in the radio-frequency range (NoRH, 17 GHz). This period appears to be related to the 3-min waves from the sunspot. The magnetic field extrapolation based on SDO/HMI magnetograms shows the existence of the magnetic channel (waveguide) connecting the sunspot with the energy release region.
Conclusions: We analysed the sunspot 3-min wave dynamics and found a correlation between the oscillation power amplification and flare triggering in the region connected to the sunspot through the magnetic channel. We propose that this amplified wave flux triggered the flare. The flare occurred because of this amplified flux, however, and because a sufficient amount of free magnetic energy was accumulated in close vicinity to the magnetic channel prior to the flare. Furthermore, because of loop heating, the wave velocity (sound velocity) increased with the penetration of waves into the energy release site. The heating is shown to be able to proceed after the flare main peak owing to a further energy pumping in the form of waves from the sunspot and additional reconnection episodes in the flare region. Title: CORONAS-F observation of HXR and gamma-ray emissions from the solar flare X10 on 29 October 2003 as a probe of accelerated proton spectrum Authors: Kurt, V. G.; Yushkov, B. Yu.; Kudela, K.; Galkin, V. I.; Kashapova, L. K. Bibcode: 2015CoSka..45...42K Altcode: HXR and gamma-ray emissions in the 0.04—150 MeV energy range associated with the solar flare on 29 October 2003 (X10/3B) were observed at 20:38—20:58 UT by the SONG instrument aboard the CORONAS-F mission. We restored consecutive flare gamma-emission spectra from SONG and RHESSI data and found a good agreement of these spectra in the 0.1—10 MeV energy range. Two phases were identified which showed major changes in the spectral shape of flare emission: 20:38:00-20:44:20 UT and 20:44:20-20:58:00 UT. During the second phase an efficiency of proton acceleration increased considerably relatively to the efficiency of acceleration of high energy electrons. The pion-decay component of the flare gamma-emission was elicited statistically significant only during the second phase since 20:47:40 UT. A power law spectrum index of accelerated protons was estimated from the ratio between intensities of the pion-decay and gamma-line components. The hardest spectrum (power law index S=3.7) was at 20:48—20:51 UT when the intensity of the pion-decay emission was maximal. Our subdivision of the flare into two phases is consistent with sharp changes in the structure of the flare found by Ji et al. (2008) and Liu et al. (2009).

This flare was accompanied by GLE 66. The time profile of the pion-decay gamma-emission was compared with the GLE onset time. It was shown that both protons interacting at the Sun and the particles responsible for the GLE onset could belong to the same population of accelerated particles. Title: Editorial: solar radiophysics — recent results on observations and theories Authors: Nakariakov, Valery M.; Kashapova, Larisa K.; Yan, Yi-Hua Bibcode: 2014RAA....14....1N Altcode: Solar radiophysics is a rapidly developing branch of solar physics and plasma astrophysics. Solar radiophysics has the goal of analyzing observations of radio emissions from the Sun and understanding basic physical processes operating in quiet and active regions of the solar corona. In the near future, the commissioning of a new generation of solar radio observational facilities, which include the Chinese Spectral Radio Heliograph (CSRH) and the upgrade of the Siberian Solar Radio Telescope (SSRT), and the beginning of solar observations with the Atacama Large Millimeter/submillimeter Array (ALMA), is expected to bring us new breakthrough results of a transformative nature. The Marie-Curie International Research Staff Exchange (MC IRSES) “RadioSun” international network aims to create a solid foundation for the successful exploitation of upcoming solar radio observational facilities, as well as intensive use of the existing observational tools, advanced theoretical modeling of relevant physical processes and observables, and training a new generation of solar radio physicists. The RadioSun network links research teams from China, Czech Republic, Poland, Russia and the UK. This mini-volume presents research papers based on invited reviews and contributed talks at the 1st RadioSun workshop in China. These papers cover a broad range of research topics and include recent observational and theoretical advances in solar radiophysics, MHD seismology of the solar corona, physics of solar flares, generation of radio emission, numerical modeling of MHD and plasma physics processes, charged-particle acceleration and novel instrumentation. Title: Dynamics of the hard X-ray, gamma-ray, and microwave emission of solar flares produced by the active region NOAA 0069 in August 2002 Authors: Bogomolov, A. V.; Kashapova, L. K.; Myagkova, I. N.; Tsap, Yu. T. Bibcode: 2014ARep...58..156B Altcode: Regularities have been searched for in the dynamics of characteristics of flare solar radiation during the development of the active region NOAA 0069 in the interval of August 14-24, 2002. The SONG (Solar Neutrons and Gamma rays) instrument onboard the Russian CORONAS-F Solar Observatory recorded hard X-ray and gamma-ray radiation in nine of the 30 flares of class above C5 in this active region within the indicated time interval. It was obtained that, in accordance with the development of the active region, the X- and gamma-ray flux tended to increase at the flare maxima while the hard X-ray spectral index tended to decrease; flares with a harder radiation spectrum occurred in the sunspot umbra, i.e., in the region with the strongest magnetic fields. Title: Analysis of time structure of the radio and HXR-emission of solar flares produced by AR0069 and their connection with characteristics of SEP events Authors: Myagkova, Irina; Kashapova, Larisa; Miteva, Rositsa; Bogomolov, Andrew Bibcode: 2014cosp...40E2212M Altcode: The results of the experimental investigation of solar energetic particles acceleration and propagation based on the study of delays between radio and X-rays emission of flares produced by the active region 0069 in August 2002 are present. Parameters of SXR and HXR photon spectrum as characteristics of acceleration processes were compared with SEP flux, their maximal energy and spectral index. Structure analysis of delays between microwave, meter and X-ray emission was carried out in order to study processes of accelerated at the Sun particle propagation and possible mechanisms of additional acceleration. It was obtained that during this series of flares more powerful SEP events with higher energies were observed in time flares with the minimal delay between microwave and HXR emission. The obtained results are discussed in respect to possible models of the SEP propagation. Title: On the Flat Gradual Phase of the 21 July 2013 Flare Authors: Kashapova, Larisa; Sych, Robert; Zhdanov, Dmitrii; Tokhchukova, Susanna Bibcode: 2014cosp...40E1413K Altcode: We present results of study of energy release process in the C3.1 solar flare occurred on July 21, 2013. This event demonstrated about 30-minutes duration flat period in the X-ray flux curve in the 3-12 keV energy band during the gradual phase of the flare. Existence of this particular shape period was confirmed by EUV observations by EVE/SDO and microwave data. The reasons of such long suppression of plasma cooling are studied using the analysis of temporal profiles of EUV, X-ray, microwave emission and plasma parameters (temperature and emission measure). The aim of the study is the revealing and analysis of quasi-periodic pulsations which could be an indicator of the energy input or cooling suppressing during the studied period. Special attention is given to the analysis of microwave spectra obtained by RATAN-600 and Badary Broadband Microwave Spectropolarimeters (BBMS). The obtained results are discussed from the point of view of different mechanisms explaining the long duration events (LDE). Title: CORONAS-F detection of gamma-ray emission from the solar flare on 29 October 2003 Authors: Kurt, Victoria; Kashapova, Larisa; Yushkov, Boris; Kudela, Karel; Galkin, Vladimir Bibcode: 2014cosp...40E1705K Altcode: Appreciable HXR/gamma-ray emissions in the 0.015-150 MeV energy range associated with the solar flare on 29 October 2003 (X10/3B) were observed at 20:41-20:58 with the SPR-N and SONG instruments onboard the CORONAS-F mission. Two time intervals were identified which showed major changes in the intensity of these emissions. To specify the details of the spectral changes with time, we fitted the SONG energy loss spectra with a three-component model of incident gamma-ray spectrum: (1) a power law in energy, assumed to be due to electron bremsstrahlung; (2) a broad continuum produced by nuclear de-excitation gamma-lines; and (3) a broad gamma-line generated from pion decay. We study the relationship between non-imaging observations, particularly between time of pion-decay emission onset and motions in this solar flare, using HXR foot points (FP) separation and flare shear temporal behavior presented by (Ji et al., 2008). In this work it was shown that significant FP converging and unshearing motion occurred during the first flare interval. During this interval the primary bremsstrahlung extended to tens of MeV and de-excitation gamma-lines dominated. During the second interval after 20:45 the FPs began to move apart. We found out that starting from 20:46, the gamma-emission spectrum revealed a feature attributed to pion-decay. It means that the effective acceleration of protons to energies above 300 MeV (pion-production threshold) occurred coincidently with a change of the flare magnetic structure. The maximum intensity of the pion-decay gamma emission was observed at 20:49 and proved to be 2.0•10-4 photons cm-2 s-1 MeV-1 at 100 MeV. This flare was accompanied by GLE-66. Using the data of the world neutron monitor network, we found its onset as 20:59 which corresponds to a reasonable propagation time of protons with ~ 0.5-2 GeV energy on the assumption that proton acceleration began at 20:46. Title: The subsecond pulses during the August 10, 2011 flare by observations of RATAN-600 and the 4-8 GHz Siberian solar spectropolarimeter Authors: Kashapova, L. K.; Tokhchukova, S. Kh.; Zhdanov, D. A.; Bogod, V. M.; Rudenko, G. V. Bibcode: 2013Ge&Ae..53.1021K Altcode: We present the results of a study of the subsecond pulses (SSPs) registered in the microwaves during the C2.4 solar flare. The event occurred on August 10, 2011, in the 11236 active region near the western limb and reached a maximum at 0935 UT. Subsecond pulses were registered by RATAN-600 for the first time when this flare reached its maximum. The fact of detection of SSPs was confirmed by simultaneous observations carried out with a spectropolarimeter at the Radio Astrophysical Observatory, Institute of Solar-Terrestrial Physics. A former analysis of the emission nature of the main flare source revealed the presence of a high-temperature ( T > 30 MK) source that determined both the microwave and X-ray emission parameters of this event. We have compared the temporal variations of the SSPs microwave emission with the variations of the plasma parameters (temperature and emission measure) taken from observations with the FERMI space telescope with a subsecond time resolution. The obtained results suggest that the nature of SSP generation, as well as of the flare itself, was determined by the high-temperature source. Title: First results of radio observations of the sun and powerful discrete radio sources using the Irkutsk Radar Authors: Vasil'ev, R. V.; Kushnarev, D. S.; Kashapova, L. K.; Lebedev, V. P.; Medvedev, A. V.; Nevedimov, N. I.; Ratovskii, K. G. Bibcode: 2013ARep...57..872V Altcode: Using the Irkutsk Incoherent Scattering Radar, it is demonstrated that the high sensitivity of such radars, which are usually used for studies of the Earth's ionosphere, also enables their use in a passive mode for observations of astronomical radio sources. Observations of solar flares accompanied by coronal mass ejections and of quasi-stationary radio sources on the Sun have been carried out. In addition, scintillations of several of the brightest discrete radio sources (Cygnus A, Cassiopeia A, and the Crab Nebula) have been studied over several months. These data can also be useful for studies of the ionosphere and interplanetary space. Title: Coronal mass ejections in July 2005 and an unusual heliospheric event Authors: Livshits, M. A.; Belov, A. V.; Shakhovskaya, A. I.; Eroshenko, E. A.; Osokin, A. R.; Kashapova, L. K. Bibcode: 2013CosRe..51..326L Altcode: Using the events in July 2005 as an example, the causes and peculiarities of Forbush effects produced by solar sources remote from the central zone are discussed. The event in question differs from other effects observed at the periphery of interplanetary disturbances by strong variations in cosmic rays on the background of weak disturbances in the solar wind and magnetic field of the Earth. The cloud of magnetized plasma ejected from the Sun was large and fast, but it passed to the west from the Sun-Earth line. According to performed estimates, the mass of the ejected substance was close to the upper boundary of mass for coronal mass ejections (CMEs). Anomalous parameters and high modulation capability of the formed solar wind disturbance are explained, in particular, by the fact that it combined several CMEs and that the last fast disturbance was prepared by a series of impulsive events in the active region of the Sun. Usually, such a great mass is ejected directly after the main energy release in strong solar flares. In the given case, a powerful MHD disturbance occurred approximately half an hour after a maximum of hard X-ray burst under the conditions when gas pressure in the flare loops became close to magnetic pressure, which was just a premise of the largescale ejection. Title: Modeling of Hα Eruptive Events Observed at the Solar Limb Authors: Kotrč, P.; Bárta, M.; Schwartz, P.; Kupryakov, Y. A.; Kashapova, L. K.; Karlický, M. Bibcode: 2013SoPh..284..447K Altcode: 2012SoPh..tmp..290K; 2012SoPh..tmp..269K We present spectra and slit-jaw images of limb and on-disk eruptive events observed with a high temporal resolution by the Ondřejov Observatory optical spectrograph. Analysis of the time series of full width at half-maximum (FWHM) in Hα, Hβ, and radio and soft X-ray (SXR) fluxes indicates two phenomenologically distinct types of observations which differ significantly in the timing of FWHM and SXR/radio fluxes. We investigated one such unusual case of a limb eruptive event in more detail. Synthesis of all observed data supports the interpretation of the Hα broadening in the sense of regular macroscopic plasma motions, contrary to the traditional view (emission from warm dense plasma). The timing and observed characteristics indicate that we may have actually observed the initiation of a prominence eruption. We test this scenario via modeling of the initial phase of the flux rope eruption in a magnetohydrodynamic (MHD) simulation, calculating subsequently - under some simplifying assumptions - the modeled Hα emission and spectrum. The modeled and observed data correspond well. Nevertheless, the following question arises: To what extent is the resulting emission sensitive to the underlying model of plasma dynamics? To address this issue, we have computed a grid of kinematic models with various arbitrary plasma flow patterns and then calculated their resulting emission. Finally, we suggest a diagnostics based on the model and demonstrate that it can be used to estimate the Alfvén velocity and plasma beta in the prominence, which are otherwise hard to obtain. Title: Microwave Quasi-periodic Radio Pulsations in the 2012 March 08 Solar Flare Authors: Zhdanov, D. A.; Kashapova, L. K.; Altyntsev, A. T.; Myshyakov, I. I.; Zandanov, V. V. Bibcode: 2013CEAB...37..563Z Altcode: We describe microwave observations of quasi-periodic pulsations from the C6.8 flare on 2012 March 08. The radio observations were made by the Siberian Solar Radio Telescope and Siberian Solar Radio Spectropolarimeter. The microwave quasi-periodic pulsations were accompanied by hard X-ray emissions which were obtained by the Fermi Gamma-ray Space Telescope. We considered both magnetohydrodynamic oscillations and injection of accelerated electrons as the possible cause of microwave pulsations. Title: On the Possible Mechanisms of Energy Release in a C-class Flare Authors: Kashapova, L. K.; Tokhchukova, S. K.; Rudenko, G. V.; Bogod, V. M.; Muratov, A. A. Bibcode: 2013CEAB...37..573K Altcode: We present the study of the C2.4 flare which occurred at 9:35 UT, 2011 August 10 in the AR 11263 near the western limb. It was observed by RATAN-600 and the Siberian Solar Radio Spectropolarimeter in microwaves (MW) and by RHESSI and FERMI in hard X-rays (HXR). A peculiarity of this event was the detection of HXR flux with energies above 25 keV that is not typical for such weak flares. The good correlation between HXR and MW time profiles indicates the generation of both HXR and MW emission by a common population of electrons. Results of fitting the HXR spectra revealed that the flare emission of energies above 25 keV could be generated both by non-thermal electrons and a high-temperature source (T> 30 MK). We reconstructed the microwave spectra using the GX_Simulator code for 3D modeling of gyrosynchrotron microwave emission (Fleischmann et al., 2011) . The input flare plasma parameters were obtained from HXR spectra and the magnetic field structure was obtained by extrapolation of the photospheric magnetic field from HMI/SDO. The results were compared with existing theoretical models and observations of other authors. Title: On a Signature of a Flux-rope Formation by Vortex Motions in its Footpoint Authors: Kotrč, P.; Bárta, M.; Kupryakov, Yu. A.; Kashapova, L. K. Bibcode: 2013CEAB...37..513K Altcode: We analyzed Hα spectrograms and slit-jaw filtergrams of active regions NOAA 10311 and 10314 observed by the Ondřejov flare spectrograph near the western limb on March 19, 2003. Several pre-flares and medium flares C, M, X (according to GOES classification) occurred in this active region during our period of observation. We observed a process of intensive creation of an active region filament. Then the filament changed its contrast in relation to the surrounding chromosphere. From details observed in the filtergrams and spectra we conclude that during this process the filament/flux-rope was twisted by vortex motions in its footpoint. The energy accumulated gradually in the configuration of magnetic field was then released during a series of flares. We discuss the observed phenomena and try to explain them in frame of generally accepted models of physical processes in solar flares. Title: On a Flat-shape Emission in the Solar Flare on 7th June 2012 Authors: Kotrč, P.; Kupryakov, Yu. A.; Kashapova, L. K.; Bárta, M. Bibcode: 2013CEAB...37..555K Altcode: We present results of the study of the C1.5 solar flare~(SOL2012-06-07T05:56) which occurred on June 7, 2012. This weak flare showed an extraordinary long flat emission in the X-ray flux curve in the 3-12 keV energy band. Duration of this flat period was about 10 minutes while the duration of the flare was almost 20 minutes. As this particular shape was observed both by RHESSI and FERMI, it could not be caused by an instrumental effect. We analyzed the optical spectra and slit-jaw images from the solar spectrograph in Ondřejov and in the hard X-ray by RHESSI as well as EUV data obtained by SDO and all available microwave data. We found that the "flat emission" period was also observed in microwaves (5-17 GHz). During this period the motion of the flare source from the spot to south direction was revealed. A localized maximum of the chromospheric emission was also shifting in the same direction. Quasi-periodic pulsations with

periods of about 5 minutes were detected in evolution of the electron temperature that is an evidence of the energy input during the "flat emission" period. Title: Relationship between nonthermal and gasdynamic processes in powerful solar flares Authors: Livshits, M. A.; Kashapova, L. K. Bibcode: 2012Ge&Ae..52..892L Altcode: The relationship between gas-dynamic processes and particle acceleration is illustrated using three examples. For the flare of July 6, 2006, observations show that explosive evaporation of the chromosphere occurs in the pulse phase. In addition, the coronal mass emission (CME) related to this flare reflects the primary energy release. In the strong limb flare of July 14, 2005, the CME observed in the external layers of the corona seems to be a consequence of repeated energy releases and plasma emissions. Apparently, this is indicated by the additional emission in the decimeter range, which is typical of posteruptive processes. An example of a weak flare during the decay phase of the strong event of April 15, 2001, was also accompanied by a decimeter burst. Title: Magnetic field dynamics based on SOHO/MDI data in the region of flares related to halo coronal mass ejections Authors: Fainshtein, V. G.; Popova, T. E.; Kashapova, L. K. Bibcode: 2012Ge&Ae..52.1075F Altcode: Variations in the photospheric magnetic field in the region of solar flares, related to halo coronal mass ejections (HCMEs) with velocities V > 1500, 1000 < V < 1500, and V < 650 km/s, have been studied based on SOHO/MDI data. Using data with a time resolution of 96 min, it has been indicated that on average the < B L> and <| B L|> field characteristics increase nonmonotonically during 1-1.5 days before a flare and decrease during 0.5-1 days after a flare for groups of ejections with V > 1000 km/s for all considered HCME groups. Angle brackets designate averaging of the measured B L magnetic field component and its magnitude | B L| within an area with specified dimensions and the center coincident with the projection onto the region where the flare center field is measured. It has been established that a solar flare related to an HCME originates when the < B L> and <| B L|> values are larger than the boundary values in the flare region. Based on 1-min data, it has been found for several HCMEs with V > 1500 km/s that the beginning of powerful flares related to ejections is accompanied by rapid impulsive or stepped variations in < B L> and <| B L|> near the center of a flare with a size of approximately 4.5°. It has been established that the HCME velocity positively correlates with the |< B L>| value at the flare onset. Title: Detection of Acceleration Processes During the Initial Phase of the 12 June 2010 Flare Authors: Kashapova, L. K.; Meshalkina, N. S.; Kisil, M. S. Bibcode: 2012SoPh..280..525K Altcode: 2012SoPh..tmp..189K; 2012arXiv1207.5896K We present an analysis of the plasma parameters during the initial phase of the 12 June 2010 flare (SOL2010-06-12T00:57). A peculiarity of the flare was the detection of γ-ray emission that is unusual for such weak and short event. The analysis revealed the presence of a flare precursor detected about five minutes before the flare onset in 94 Å images which spatially coincided with the non-polarized microwave (MW) source at 17 GHz (the Nobeyama Radio Heliograph) that is the Neutral Line associated Source (NLS). A comparison of the results obtained from MW data by the Nobeyama Radio Polarimeters and the multi-frequency Siberian Radioheliograph (the new 10-antenna radio heliograph prototype at 4.6 and 6.4 GHz) and hard X-ray (HXR) observations by the Fermi Gamma-ray Space Telescope reveal the presence of accelerated electrons during the flare's initial phase. The analysis of MW and HXR spectra also confirms the presence of accelerated particles. Moreover, a good temporal correlation between several light curves in different HXR energy bands and at MW frequencies indicates the generation of both HXR and MW emission by a common population of accelerated electrons. Detection of accelerated particles during the initial phase of the flare and soft-hard-harder (SHH) behavior of the spectra indicate several episodes of particle acceleration and confirm the non-impulsive type of the flare evolution. Title: Observation of the powerful solar flare of October 27, 2002 on the far side of the sun Authors: Vybornov, V. I.; Livshits, M. A.; Kashapova, L. K.; Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B.; Tret'yakov, V. I.; Boynton, W.; Shinohara, K.; Hamara, D. Bibcode: 2012ARep...56..805V Altcode: 2012AZh....89..888V Observations of the hard X-ray and radio event of October 27, 2002 are analyzed. This flare was observed from near-Martian orbit by the HEND instrument developed at the Space Research Institute of the Russian Academy of Sciences and installed on the Mars Odyssey satellite. Although this powerful flare was observed far over the eastern solar limb, the extended source associated with the flare was detected by RHESSI at energies up to about 60 keV. The eruptive event was observed in the radio at the Nobeyama Radio Observatory. The properties of the X-ray radiation are used to calculate the spectrum of the accelerated electrons responsible for the observed radiation, assuming that the target is thick for a Martian observer and thin for a terrestrial observer. The results are compared with the results of radio observations. The conditions for electron propagation in the corona are discussed. Title: On Detection of Balmer-Series Lines Response to Accelerated Particles in Solar Flares Authors: Kotrč, P.; Kashapova, L. K.; Kupryakov, Y. A. Bibcode: 2012ASPC..454..337K Altcode: Comparison of the Balmer series lines with HXR and microwave emissions are used as tools for study of the chromospheric response to effects of accelerated particle beams in solar flares. We studied the Hα and Hβ lines and the ratio of the line profiles for several solar flares observed with a high cadence to find and to analyze variations predicted from the theoretical simulations of Kašparová & Heinzel (2002). The profiles extracted at individual kernels during different flare phases were analyzed with respect to the radio and X-ray data patterns. We found that the theoretical predictions of the Hα/Hβ line profile ratios and the observations were in a good qualitative agreement. However, as concerns quantitative correspondence, we found some difference in position of the predicted profile ratio maxima, moment of arising and the duration of the effect, influence of energy cutoff of electron beam. We try to find some explanations for those discrepancies and discuss perspectives of simultaneous observations of Balmer series lines. Title: Particle transport effects in solar flares for interpretation of HXR and MW emission: theory versus observations Authors: Zharkova, V. V.; Taras, S.; Kashapova, L.; Kuznetsov, A. Bibcode: 2011AGUFMSH41A1893Z Altcode: In this paper we discuss the effects of different energy loss mechanisms on resulting hard X-ray and MW emission of beam electrons injected in the loop top in the corona and precipitating into loop footpoints. For this purpose we use numeric solutions of Fokker-Planck equation considering collisional and Ohmic energy losses and anisotropic scattering in converging magnetic field for different scenarios of particle injections with respect to pitch angle anisotropy and different flaring atmosphere models. Electron beam distributions obtained in collisional, collisional plus Ohmic losses, collisional plus Ohmic plus turbulent losses for the models with different magnetic convergence factors are compared. The resulting HXR and MW emission and polarisation for each models are compared and implications for the interpretation of observations are also discussed. Title: Effect of a self-induced electric field on the electron beam kinetics and resulting hard X-ray and microwave emissions in flares Authors: Zharkova, V. V.; Meshalkina, N. S.; Kashapova, L. K.; Altyntsev, A. T.; Kuznetsov, A. A. Bibcode: 2011Ge&Ae..51.1029Z Altcode: The kinetics of beam electron precipitation from the top of a loop into the solar atmosphere with density gradients and an increasing magnetic field have been generally described. The Fokker-Planck equations are solved with regard to Coulomb collisions and the effect of the electric field induced by this beam. The photon spectra and polarization degree in hard X-ray (10-300 keV) and microwave (1-80 GHz) emissions are simulated under different assumptions regarding the beam electron distribution function. The simulation results are compared with the flare observations on March 10, 2001, and July 23, 2002, visible at different position angles. It has been indicated that the coincidence of the theoretical photon spectra with simultaneous observations of the hard X-ray and microwave emissions of these flares is the best for models that not only take into account collisions, but also the electric field induced by electron fluxes propagating in flare loops with very weakly or moderately converging magnetic fields. Title: Physics of post-eruptive solar arcades: Interpretation of RATAN-600 and STEREO spacecraft observations Authors: Livshits, M. A.; Urnov, A. M.; Goryaev, F. F.; Kashapova, L. K.; Grigor'eva, I. Yu.; Kal'Tman, T. I. Bibcode: 2011ARep...55..918L Altcode: 2011AZh....88..997L Results of simultaneous measurements of radiation fluxes from post-eruption arcades on the Sun at 171, 195, 284, and 304 Å (from STEREO spacecraft data) and at radio wavelengths (from the RATAN-600 radio telescope) are presented. An original probabilistic approach developed earlier by Urnov was used to determine the differential emission measure. This method requires no regularization, and the obtained results do not depend on the choice of the temperature grid. This approach has yielded the differential measure of emission at temperatures approximately from 0.3 to 15 MK. The subsequent calculation of thermal magnetobremsstrahlung in a multi-temperature model with the magnetic field decreasing with height produces a spectrum similar to that observed on RATAN-600. Thus, in many non-stationary events with modest powers, a thermal multi-temperature model is quite able to explain the emission of post-eruption arcade systems, and it is not necessary to invoke the emission of accelerated particles. The proposed model enables direct estimation of the ratio of the magnetic and gas pressures at the tops of post-eruption arcades, and determination of the conditions required for the origin of secondary nonstationary processes in the decay stage of the main flare. Title: Erratum to: "Culmination of the flare activity of group 10786 in July 2005: X-ray observations from near-Mars and near-Earth orbits" Authors: Livshits, M. A.; Golovin, D. V.; Kashapova, L. K.; Mitrofanov, I. G.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B.; Tret'yakov, V. I.; Boynton, W.; Shinohara, K.; Hamara, D. Bibcode: 2011ARep...55..943L Altcode: No abstract at ADS Title: Diagnostics of electron beam properties from the simultaneous hard X-ray and microwave emission in the 2001 March 10 flare Authors: Zharkova, V. V.; Meshalkina, N. S.; Kashapova, L. K.; Kuznetsov, A. A.; Altyntsev, A. T. Bibcode: 2011A&A...532A..17Z Altcode: 2011arXiv1105.3508Z; 2010A&A...532A..17Z Context. Microwave (MW) and hard X-ray (HXR) data are thought to be powerful means of investigating the mechanisms of particle acceleration and precipitation in solar flares, reflecting different aspects of electron interaction with ambient particles in the presence of a magnetic field. Simultaneous simulation of HXR and MW emission with the same populations of electrons is still a big challenge for interpreting observations of real events. Recent progress in simulations of particle kinetics with the time-dependent Fokker-Planck (FP) approach offers an opportunity to produce this interpretation.
Aims: In this paper we apply the FP kinetic model of precipitation of electron beam with energy range from 12 keV to 1.2 MeV to the interpretation of X-ray and MW emissions observed in the flare of 2001 March 10.
Methods: The theoretical HXR and MW emissions were calculated by using the distribution functions of electron beams found by solving time-dependent approach in a converging magnetic field for anisotropic scattering of beam electrons on the ambient particles in Coloumb collisions and Ohmic losses.
Results: The simultaneously observed HXR photon spectra and frequency distribution of MW emission and polarization were fit by those simulated from FP models that include the effects of electric field induced by beam electrons and precipitation onto a converging magnetic loop. Magnetic field strengths in the footpoints on the photosphere were updated with newly calibrated SOHO/MDI data. The observed HXR energy spectrum above 10 keV is shown to be a double power law that was precisely fit by the photon HXR spectrum simulated for the model including the self-induced electric field but without magnetic convergence. The MW emission simulated for different models of electron precipitation revealed a better fit (above 90% confidence level) to the observed distribution at higher frequencies for the models combining collisions and electric field effects with a moderate magnetic field convergence of two. The MW simulations were able to reproduce closely the main features of the MW emission observed at higher frequencies: the spectral index, the frequency of peak intensity and the frequency of the MW polarization reversal, while at lower frequencies the simulated MW intensities are lower than the observed ones. Title: Culmination of the flare activity of Group 10786 in July 2005: X-Ray observations from near-mars and near-earth orbits Authors: Livshits, M. A.; Golovin, D. V.; Kashapova, L. K.; Mitrofanov, I. G.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B.; Tret'yakov, V. I.; Boynton, W.; Shinohara, K.; Hamara, D. Bibcode: 2011ARep...55..551L Altcode: 2011AZh....88..598L A detailed study of two major solar flares that occurred in Group 10786 at the time of its disappearance behind the western limb is presented. The flares of July 14, 2005 were previously studied fairly poorly, as no RHESSI hard X-ray observations were available for themaxima of the twomost powerful of these flares. Observations carried out using the HEND equipment (on the Mars Odyssey spacecraft) developed at the Institute for Space Research in Moscow are used here to fill this gap. In the first flare, an intense, impulsive burst occurred at 07:23 UT, about 1.5 h after the onset of a weak, prolonged event. While processes in the neighborhood of the northern spot dominated in the flares of July 5-9, a powerful impulsive energy release on July 14 emerged when the flare process that originated in the North reached the southern spot. Our analysis of the flare activity of this medium-sized group reveals a gradual enhancement of the flare activity and a strong interaction between the acceleration above the magnetic-field neutral line and in the immediate vicinity of the spots. At the time of the culmination of the flare activity in the group on July 13 and 14, the pattern of nonstationary processes changes: fast coronal mass ejections form after a series of impulsive energy-release events. Spacecraft observations of the burst of July 14 after 11 UT at points separated in longitude (on RHESSI and Mars Odyssey) revealed clear anisotropy of the flare emission at energies exceeding 80 keV. Title: The effect of energetic particle beams on the chromospheric emission of the 2004 July 25 flare Authors: Zharkova, V. V.; Kashapova, L. K.; Chornogor, S. N.; Andrienko, O. V. Bibcode: 2011MNRAS.411.1562Z Altcode: In this paper the role of particle beams in the generation of a close spatial and temporal correlation between hard X-ray (HXR) energy and Hα line emission bursts in the solar flare of 2004 July 25 is discussed. The light curves in the HXR emission and Hα line reveal that the pre-flare and main flare events are correlated with the variations of line-of-sight (LOS) magnetic flux. The HXR emission shows three main bursts during the main flare phase, which are accompanied by Hα intensity increases. The latter appear in 10 locations (kernels) at different times in succession; the kernel locations are associated with strong magnetic sources situated on the opposite side from the magnetic neutral line (MNL). The appearance of Hα kernels in the pre-flare event and those at the start of the main event ia correlated very closely (within a few seconds) with the HXR emission observed by the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) (HXR+Hα kernels), while the appearance of some others, not associated with HXR emission, was delayed by tens of seconds. Electron-beam parameters were derived from the RHESSI spectra in which the observed HXR photon flux was corrected for the self-induced electric field effect. Possible implications of this electric field on the production of transient magnetic fields observed during the flare are discussed. The Hα emission observed during the first burst was simulated in a hydrodynamic atmosphere for 5 levels plus a continuum hydrogen atom with the full non-local thermodynamic equilibrium (non-LTE) approach combining radiative, thermal and non-thermal excitation and ionization by an electron beam with the derived parameters. The simulated temporal profiles of Hα emission produced by non-thermal hydrogen excitation revealed a very good fit to the observed ones in the HXR+Hα kernels and 10-20 s delays in the other kernels. This allows us to speculate that Hα emission is caused mainly by electrons in the HXR+Hα kernels and mainly by protons in the others. Title: On the Chromospheric Response At The Pre-CME Phase Of The 18 March 2003 Solar Flare Authors: Kashapova, L. K.; Kotrč, P.; Kupryakov, Yu. A. Bibcode: 2011CEAB...35..125K Altcode: We present a study of the X1.5 solar flare that occurred in the AR 10314 and was followed by a partial halo CME. Our main target was to find characteristic parameters associated with the pre-CME and CME phase. Special attention is devoted to parameters obtained from chromospheric observations. We analysed Hα spectra and Hα slit-jaw images from the Ondřejov Multichannel Flare Spectrograph observed with a high temporal resolution. Comparison of the Hα shift and the HXR data revealed that before the CME onset each injection of accelerated particles to the chromosphere was followed by upward mass motions with a delay of about 45 seconds. We did not find a significant value of the Hα shift that could be associated with Moreton wave velocities during the ejection phase. All values of the Hα blue shift corresponded to the evaporation process. Thus the role of the chromosphere in the CME preparatory phase was to increase the amount of the mass above the flare region which was then released by the CME. Title: Study of energy release and transport processes of the 14th July 2005 flares in AR~10786 Authors: Sizykh, T. S.; Kashapova, L. K. Bibcode: 2011CEAB...35...93S Altcode: We studied acceleration processes in two large flares (M1.0 and X1.2) that originated in the active region 10786 on 14 July 2005 when the region was partially occulted at the west limb of the Sun. The M1.0 flare had a thermal spectrum while the X1.2 flare had a significant non-thermal component. A comparison of temperature (T) vs. emission measure (EM) diagrams and spectral index vs. flux diagrams for the X1.2 flare shows that the impulsive phase corresponded to the period of rising T and EM. The T vs. EM diagrams of both flares had small turns, near the time of flare impulsive phase, which could be associated with CME events. Title: The post-eruptive arcade formation in the limb event on July 31, 2004 from microwave solar observations with the RATAN-600 radio telescope Authors: Grigoryeva, I. Yu.; Kashapova, L. K.; Borovik, V. N.; Livshits, M. A. Bibcode: 2010SunGe...5...58G Altcode: A CME/flare event occurred at the western limb on 31 July 2004. Five successive multi-wavelength scans in centimeter range were obtained with the RATAN-600 radio telescope starting at the early stage of post-eruptive arcade formation (24 min after a C8.3 flare peak) and lasting for 4 hours. Microwave radio emission of the arcade was rather intense at initial stage indicating a predominant contribution of thermal emission and then considerably decreased during the decay phase. Its maximum was co-spatial with the 195 Å Fe XII loop tops. At the end of microwave observations the contribution of the emission from accelerated particles became significant. The similarity of microwave characteristics of two eruptive events (on 31 July 2004 at the western limb and on 25 January 2007 at the eastern limb) is shown. Title: Catalogue of solar flare spectra observed at Ondrejov in 1998-2007 Authors: Kupryakov, Yu. A.; Kotrc, P.; Kashapova, L. K. Bibcode: 2010SunGe...5...61K Altcode: We present a catalogue of solar flare data observed with two Ondřejov optical spectrographs during 1998-2007 years. This database was created to enable the data processing more convenient for users interested in the study of the energy release and transport in solar flares. The spectra and Hα filtergrams were obtained both at the Multichannel Flare Spectrograph (MFS) and at the Large Horizontal Spectrograph (HSFA2). The catalogue contains basic information about time of observation of solar flares, their location in AR, importance, availability of related data at the selected X-ray, EUV and radio instruments. The catalogue is available at www.asu.cas.cz/~sos/flare_archive.html. Title: Latitudinal and Solar-Cycle Variations of the White-Light Corona from SOHO/LASCO Observations Authors: Fainshtein, V. G.; Tsivileva, D. M.; Kashapova, L. K. Bibcode: 2010SoPh..267..203F Altcode: 2010SoPh..tmp..182F SOHO/LASCO data were used to obtain the latitudinal and radial distributions of the brightness of the K- and F-corona in the period of 1996 - 2007, and their solar-cycle variations were studied. Then an inversion method was employed to obtain the radial distributions of the electron density Ne(R,θ) for various latitude values on the coronal images. Our values of Ne(R,θ) are in good agreement with the findings of other authors. We found that in an edge-on streamer belt the electron density, like the K-corona brightness, varies with distance more slowly in the near-equatorial rays than in near-polar regions. We have developed a method for assessing the maximum values of the electron density at the center of the face-on streamer belt in its bright rays and depressions between them. Not all bright rays observed in the face-on streamer belt are found to be associated with an increased electron density in them. Mechanisms for forming such rays have been suggested. Title: Properties of the magnetic fields of coronal holes with active regions Authors: Fainshtein, V. G.; Stepanian, N. N.; Rudenko, G. V.; Malashchuk, V. M.; Kashapova, L. K. Bibcode: 2010BCrAO.106....1F Altcode: We determine the structure of the magnetic fields of coronal holes (CHs) and investigate its change in connection with the emergence of active regions (ARs) in CHs. Based on our observations in the HeI 1083 nm line performed with the CrAO TST-2 telescope, we have selected CHs of two types: without (15 CHs) and with (28 CHs) ARs. Magnetograms obtained at the Kitt Peak National Solar Observatory have been used to calculate the magnetic fields of the same objects. We have calculated magnetic field characteristics by Rudenko’s method in the potential approximation at several heights in the corona, namely, the average (over the CH area) radial field component < B r > and its magnitude <| B r |/ B> and the maximum and minimum (over the CH area) values of B r . The distributions of the isolines of these parameters superimposed on the CH images and the field lines of the calculated magnetic field have been constructed with resolutions of 33.4″ and 100.2″ on the solar surface. Analysis of these data has yielded the following results:

The field lines originating in CHs without ARs are open or very high loops that are closed outside CHs. The latter occurs in completely or partially closed CHs. Title: Determination of Geometric and Kinematical Parameters of Coronal Mass Ejections Using STEREO Data Authors: Fainshtein, V. G.; Tsivileva, D. M.; Kashapova, L. K. Bibcode: 2010AIPC.1216..416F Altcode: We present a new, relatively simple and fast method to determine true geometric and kinematical CME parameters from simultaneous STEREO A, B observations of CMEs. These parameters are the three-dimensional direction of CME propagation, velocity and acceleration of CME front, CME angular sizes and front position depending on time. The method is based on the assumption that CME shape may be described by a modification of so-called ice-cream cone models. The method has been tested for several CMEs. Title: Investigation of acceleration processes of the 14th july 2005 flare series occurred in ar 10786 Authors: Sizykh, Tatyana; Kashapova, Larisa Bibcode: 2010cosp...38.1975S Altcode: 2010cosp.meet.1975S We present the results of acceleration process study in the flare series occurred 14th July 2005 on the western limb of the Sun. Our investigation is based on HXR data obtained by RHESSI. It was observed increasing of solar flare activity with X1.2 class flare at its culmination. The presence of accelerated electrons (the power-law component of HXR spectrum for energies more than 25 keV) was clearly signified only in the first (C3.8) and the last of studied flares. We applied lgT-1/2lgEM diagrams ( Jakimiec et al,1986) for quantitative study of HXR spectrums for all flares. For analysis of the flares showed presence of significant flux of accelerated electrons we also used diagrams made on base of parameters obtained from non-thermal part of the spectrum (flux, spectral index, spectral curvature, Grigis Benz 2009). The possible scenario of evolution of this active region is discussed. Title: Directivity of HXR Solar Flare Emission Obtained from Stereoscopic Observations by Mars Odyssey (HEND), RHESSI and CORONAS-F (SONG) Authors: Livshits, Moisey; Golovin, Dmitry; Mitrofanov, Igor; Kozyrev, S. Alexander; Litvak, Maxim; Tretyakov, Vladislav; Sanin, Anton; Boynton, William V.; Kashapova, Larisa; Myagkova, Irina; Bogomolov, Andrey Bibcode: 2010cosp...38.2984L Altcode: 2010cosp.meet.2984L Two powerful X-Ray flares were observed on 2005, July 14 by three spacecrafts whose heliolon-gitudes were spaced on 39 degrees. The flares were observed, as projected on the solar disc by Mars Odyssey (HEND) and seeing almost directly on the limb by RHESSI and CORONAS-F. The most intensive hard X-ray and gamma-ray flare (up to 2 MeV) was observed by HEND and SONG on 07:23 UT, and measured time profiles were similar, but the spectra were quite rather different. Particular pulses of flares were studied by data from different instruments with dif-ferent heliolongitudes, and conclusion was drawn that difference between fluxes at these flares is more likely due to a directivity of radiation. The emission directivity was more clearly seen for the source at the top of flare loop for burst observed near 11:00 UT. Title: Diagnostics of the beam anisotropy from the HXR and MW emission data in the flare of 10 March 2001. Authors: Meshalkina, Natalia; Zharkova, Valentina; Kashapova, Larisa; Altyntsev, Alexander; Kuznetsov, Alexey Bibcode: 2010cosp...38.1963M Altcode: 2010cosp.meet.1963M Microwave and hard X-ray data are thought to be powerful mean for investigating the mech-anisms of particle acceleration and precipitation in solar flares. In this paper X-ray and mi-crowave emission is investigated for the flare of 10 March 2010 previously studied by Altyntsev et al. (2008), who concluded there was a beamlike anisotropy in the particle distribution in the event. The simulations of HXR and MW emissions produced by beam electrons with en-ergies from 12keV to 1.2 MeV are carried out by taking into account anisotropic scattering in converging magnetic field of beam electrons in Coloumb collisions and Ohmic losses by using time-dependent Fokker-Planck approach (Zharkova at al, AA, 2010; Kuznetsov and Zharkova, AA, 2010). The simulated HXR photons spectra, MW emission spectra (1-80 GHz) and polar-ization are compared with the observed ones using the magnetic field values updated with new calibrated MDI. Similar to the previous simulations (Altyntsev et al, 2008), we conclude the absence of a detectable magnetic field convergence in both HXR and MW emission. However, the simulated HXR photon spectra, MW emission and polarization reveal the best fit for the models including the effect of electric field induced by beam electrons show the both emission emitted from a slightly tilted loop in the flare location and not in the perpendicular direction deduced in earlier simulations. Title: Some properties of the continuous latitude distributions of the brightness of the K and F coronas as deduced from the LASCO data Authors: Fainshtein, V. G.; Kashapova, L. K.; Tsivileva, D. M. Bibcode: 2009Ge&Ae..49.1106F Altcode: Using two new methods for separating the K and F coronas and the LASCO C2 and C3 coronagraph data, continuous latitude distributions of the brightness of the K and F coronas have been obtained and examined as a function of the distance for different solar activity phases. Title: High-Energy Emission from a Solar Flare in Hard X-rays and Microwaves Authors: Kundu, M. R.; Grechnev, V. V.; White, S. M.; Schmahl, E. J.; Meshalkina, N. S.; Kashapova, L. K. Bibcode: 2009SoPh..260..135K Altcode: 2009arXiv0908.0385K We investigate accelerated electron energy spectra for different sources in a large flare using simultaneous observations obtained with two instruments, the Nobeyama Radio Heliograph (NoRH) at 17 and 34 GHz, and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) at hard X-rays. This flare is one of the few in which emission up to energies exceeding 200 keV can be imaged in hard X-rays. Furthermore, we can investigate the spectra of individual sources up to this energy. We discuss and compare the HXR and microwave spectra and morphology. Although the event overall appears to correspond to the standard scenario with magnetic reconnection under an eruptive filament, several of its features do not seem to be consistent with popular flare models. In particular we find that (1) microwave emissions might be optically thick at high frequencies despite a low peak frequency in the total flux radio spectrum, presumably due to the inhomogeneity of the emitting source; (2) magnetic fields in high-frequency radio sources might be stronger than sometimes assumed; (3) sources spread over a very large volume can show matching evolution in their hard X-ray spectra that may provide a challenge to acceleration models. Our results emphasize the importance of studies of sunspot-associated flares and total flux measurements of radio bursts in the millimeter range. Title: Eruptions of Magnetic Ropes in Two Homologous Solar Events of 2002 June 1 and 2: a Key to Understanding an Enigmatic Flare Authors: Meshalkina, Nataliya S.; Uralov, Arkadiy M.; Grechnev, Victor V.; Altyntsev, Alexander T.; Kashapova, Larisa K. Bibcode: 2009PASJ...61..791M Altcode: 2009arXiv0908.0384M The goal of this paper is to understand the drivers, configurations, and scenarios of two similar eruptive events, which occurred in the same solar active region 9973 on 2002 June 1 and 2. The June 2 event was previously studied by Sui, Holman, and Dennis (2006, ApJ, 646, 605; 2008, Adv. Space Res., 41, 976), who concluded that it was challenging for popular flare models. Using multi-spectral data, we analyzed a combination of the two events. Each of the events exhibited an evolving cusp-like feature. We have revealed that these apparent ``cusps'' were most likely mimicked by twisted magnetic flux ropes, but unlikely to be related to the inverted Y-like magnetic configuration in the standard flare model. The ropes originated inside a funnel-like magnetic domain whose base was bounded by an EUV ring structure, and the top was associated with a coronal null point. The ropes appear to be the major drivers for the events, but their rise was not triggered by reconnection in the coronal null point. We propose a scenario and a three-dimensional scheme for these events in which the filament eruptions and flares were caused by interaction of the ropes. Title: High-Energy Emission from a Solar Flare in Hard X-Rays and Microwaves Authors: Kundu, Mukul R.; Grechnev, V. V.; White, S. M.; Schmahl, E. J.; Meshalkina, N. S.; Kashapova, L. K. Bibcode: 2009SPD....40.1920K Altcode: We investigate accelerated electron energy spectra for different sources in a large flare using simultaneous observations obtained with two instruments, the Nobeyama Radio Heliograph (NoRH) at 17 and 34 GHz, and the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) at hard X-rays. This flare is one of the few in which emission up to energies exceeding 200 keV can be imaged in hard X-rays. Furthermore, we can investigate the spectra of individual sources up to this energy. We discuss and compare the HXR and microwave spectra and morphology. Although the event overall appears to correspond to the standard scenario with magnetic reconnection under an eruptive filament, several of its features do not seem to be consistent with popular flare models. In particular we find that (1) microwave emissions might be optically thick at high frequencies despite a low peak frequency in the total flux radio spectrum, presumably due to the inhomogeneity of the emitting source; (2) magnetic fields in high-frequency radio sources might be stronger than sometimes assumed; (3) sources spread over a very large volume can show matching evolution in their hard X-ray spectra that may provide a challenge to acceleration models. Our results emphasize the importance of studies of sunspot-associated flares and total flux measurements of radio bursts in the millimeter range. Title: Forecasting the velocity of quasi-stationary solar wind and the intensity of geomagnetic disturbances produced by it Authors: Eselevich, V. G.; Fainshtein, V. G.; Rudenko, G. V.; Eselevich, M. V.; Kashapova, L. K. Bibcode: 2009CosRe..47...95E Altcode: A brief review is given of contemporary approaches to solving the problem of medium-term forecast of the velocity of quasi-stationary solar wind (SW) and of the intensity of geomagnetic disturbances caused by it. At the present time, two promising models of calculating the velocity of quasi-stationary SW at the Earth’s orbit are realized. One model is the semi-empirical model of Wang-Sheeley-Arge (WSA) which allows one to calculate the dependence V( t) of SW velocity at the Earth’s orbit using measured values of the photospheric magnetic field. This model is based on calculation of the local divergence f S of magnetic field lines. The second model is semi-empirical model by Eselevich-Fainshtein-Rudenko (EFR). It is based on calculation in a potential approximation of the area of foot points on the solar surface of open magnetic tubes (sources of fast quasistationary SW). The new Bd-technology is used in these calculations, allowing one to calculate instantaneous distributions of the magnetic field above the entire visible surface of the Sun. Using predicted V( t) profiles, one can in EFR model calculate also the intensity of geomagnetic disturbances caused by quasi-stationary SW. This intensity is expressed through the K p index. In this paper the EFR model is discussed in detail. Some examples of epignosis and real forecast of V( t) and K p ( t) are discussed. A comparison of the results of applying these two models for the SW velocity forecasting is presented. Title: Microwave observations with the RATAN-600 radio telescope: detection of the thermal emission sources Authors: Grigoryeva, Irina Yu.; Kashapova, Larisa K.; Livshits, Moisey A.; Borovik, Valery N. Bibcode: 2009IAUS..257..177G Altcode: We report on two off-limb radio sources of microwave emission which were detected in one-dimensional RATAN-600 solar scans of the post-eruptive loops: on December 2, 2003 (off west limb) and January 25, 2007 (east limb). The microwave spectra showed that the thermal emission was predominant at the early stage of the arcade formation with a small contribution of non-thermal emission. There were no high-energy particles in these events. The microwave spectra of the radio sources associated with the tops of postflare loops show the predominant thermal emission during one hour after the eruption. In case of a small contribution from accelerated particles to the microwave emission, there is a large amount of hot plasma in the region of the loop tops after the eruption. Title: A Possible Scenario of Energy Transport in the 17th May 2002 Flare Authors: Kotrč, P.; Kashapova, L. K.; Frolova, A. S.; Kuprjakov, Yu. A. Bibcode: 2009CEAB...33..207K Altcode: We deduce the energy transport scenario from simultaneous observations in a wide range of the electromagnetic spectrum. High-temporal resolution optical and radio spectra from the Ondřejov observatory, and data obtained by RHESSI, Nobeyama Radio Observatory, Radio Solar Telescope Network (RSTN) and by SOHO (MDI and EIT) were analysed to get a complex view on the event. As follows from the microwave data the maximum of emission at 17 GHz evolved from the eastern part of the flare to the western one. Chromospheric emission of the flare originated from two eruptive centres -- eastern and western ones. While the eastern centre consisted of a single Hα kernel, the western one was rather a complex structure. These centres were associated with different HXR sources. The western centre was connected with a more mighty HXR source of 25-100 keV. We studied a correlation of the hard X-rays, radio emission and the Balmer series lines for the western centre in detail. Probable agents and scenarios of the energy transport are discussed. Title: Eruptive processes at the beginning of development of powerful flare-active regions on the sun Authors: Kashapova, L. K.; Livshits, M. A. Bibcode: 2008ARep...52.1015K Altcode: 2008AZh....85.1129K The evolution of large solar activity centers is studied, and the conditions resulting in powerful nonstationary processes are clarified. In addition to the factors that are usually considered (changes in sunspot area, the structure of magnetic fields, the character of motions), we examine to what extent observations of nonstationary processes (flares and associated coronal mass ejections) can be used to predict the development of such processes in the subsequent evolution of the activity center. We considered the example of a powerful group in October 2003, which could be observed before its appearance at the eastern limb using a spacecraft in near-Mars orbit. We plotted for events occurring in 2003 images of flares in various spectral ranges and analyzed high-energy processes in group 486, which was isolated at the beginning of its development, and then in the interrelated groups 486 and 484. The analysis of the peculiar early development of group 486 suggested that an intensification of the activity could be expected due to the emergence of new magnetic flux (and satellite groups), as well as the interaction and synchronization of two and then three large groups of the end of October 2003. In other words, in this case, extremely powerful nonstationary processes are associated with a relatively higher contribution of large-scale magnetic fields. We compare our results to analyses of motions and magnetic fields in this activity center throughout its transit across the disk from October 23 to November 5, 2003. Title: Non-thermal particle effects on the Hα and Hβ line profiles in the 18 August 2002 solar flare Authors: Kashapova, L. K.; Kotrč, P.; Kupryakov, Yu. A. Bibcode: 2008AnGeo..26.2975K Altcode: We present results of the 18 August 2002 flare analysis as an example for developing a diagnostic tool for thermal and non-thermal processes in chromospheric lines. Taking into account the hard X-ray (HXR) emission, we attempted to derive the Hα and Hβ line properties which were caused by the non-thermal electron contribution and could be useful for diagnostic purposes. The flare itself was a sequence of harder and softer bursts in HXR and we investigated three flare kernels associated with them. Two of the kernels appeared simultaneously. This phase of the flare could be observed in a broad band of wavelengths (HXR, UV, optical and microwaves). Kernel 1 did not clearly coincide with any HXR source but its intensity increased with the HXR flux rise. The flare kernel~3 did not show any significant response in microwaves, however, the related HXR flux was comparable with the flux of the previous kernels. We carried out an analysis of the difference between the Hα/Hβ profile rate in the line center at the distance of 0.5 Å from the line center. Only kernel 2 showed parameter fluctuations that were related to HXR flux evolution. The supposition of the non-thermal electron effect on the Hα/Hβ profile ratio was confirmed only at the kernel connected with the 25 50 keV HXR source. We found further confirmation that the Hα/Hβ line intensity ratio could be used as a diagnostic tool for non-thermal electron presence. Title: An Extreme Solar Event of 20 January 2005: Properties of the Flare and the Origin of Energetic Particles Authors: Grechnev, V. V.; Kurt, V. G.; Chertok, I. M.; Uralov, A. M.; Nakajima, H.; Altyntsev, A. T.; Belov, A. V.; Yushkov, B. Yu.; Kuznetsov, S. N.; Kashapova, L. K.; Meshalkina, N. S.; Prestage, N. P. Bibcode: 2008SoPh..252..149G Altcode: 2008arXiv0806.4424G; 2008SoPh..tmp..145G The famous extreme solar and particle event of 20 January 2005 is analyzed from two perspectives. Firstly, using multi-spectral data, we study temporal, spectral, and spatial features of the main phase of the flare, when the strongest emissions from microwaves up to 200 MeV gamma-rays were observed. Secondly, we relate our results to a long-standing controversy on the origin of solar energetic particles (SEP) arriving at Earth, i.e., acceleration in flares, or shocks ahead of coronal mass ejections (CMEs). Our analysis shows that all electromagnetic emissions from microwaves up to 2.22 MeV line gamma-rays during the main flare phase originated within a compact structure located just above sunspot umbrae. In particular, a huge (≈ 105 sfu) radio burst with a high frequency maximum at 30 GHz was observed, indicating the presence of a large number of energetic electrons in very strong magnetic fields. Thus, protons and electrons responsible for various flare emissions during its main phase were accelerated within the magnetic field of the active region. The leading, impulsive parts of the ground-level enhancement (GLE), and highest-energy gamma-rays identified with π0-decay emission, are similar and closely correspond in time. The origin of the π0-decay gamma-rays is argued to be the same as that of lower-energy emissions, although this is not proven. On the other hand, we estimate the sky-plane speed of the CME to be 2 000 - 2 600 km s−1, i.e., high, but of the same order as preceding non-GLE-related CMEs from the same active region. Hence, the flare itself rather than the CME appears to determine the extreme nature of this event. We therefore conclude that the acceleration, at least, to sub-relativistic energies, of electrons and protons, responsible for both the major flare emissions and the leading spike of SEP/GLE by 07 UT, are likely to have occurred nearly simultaneously within the flare region. However, our analysis does not rule out a probable contribution from particles accelerated in the CME-driven shock for the leading GLE spike, which seemed to dominate at later stages of the SEP event. Title: On Fast Chromospheric Responses to Microwave Subsecond Bursts Authors: Kashapova, L. K.; Kotrc, P.; Meshalkina, N. S. Bibcode: 2008ESPM...12.2.47K Altcode: We present a multi-wavelength analysis of chromosphere responses produced during the subsecond bursts detected by Siberian Solar Radio Telescope (SSRT, 5.7 GHz) on April 26, 2003 at 08:05:30 UT. The data obtained by Nobeyama Radioheliograph (NoRH, 17 and 34 GHz), Ondrejov observatory and RHESSI were also used. A correlation of multi-wavelength observations (microwave emission, hard X-rays and the video-cadence chromospheric line spectra from the Ondrejov observatory obtained with 0.04 second resolution) was performed to study fluxes on various levels of solar atmosphere before, during and after the event. The temporal resolution was high enough to resolve responses to subsecond pulses in the individual correlated fluxes and their possible interrelations. The results and possible scenario are briefly discussed from point of view of the energy transport mechanisms. Title: On Dynamics of H-alpha/H-beta Line Ratio and Non-thermal Particle Effects in Solar Flares Authors: Kotrc, P.; Kashapova, L. K.; Kuprjakov, Yu. A. Bibcode: 2008ESPM...12.2.61K Altcode: The ratio of the H-alpha?/H-beta line profiles was analyzed as a diagnostic indicator of non-thermal particle effects in solar flares. Differences between the H-alpha/H-beta profile ratio in the line center and at the distance of 0.5 Angstroms from the line center were studied in various phases of flares as concerns presence of responses to non-thermal effects. Variations of this parameter were compared with the HXR flux evolution for the 26 June 1999 and the 18 August 2002 solar flares. The sign of the parameter changed from negative to positive value only for these flare kernels where coincidence with the HXR sources indicated presence of accelerated particles. However, no such a change was found for the other kernels.

The revealed effect was compared with information obtained from correlation between the temporal fluctuations of the H? and H? line and the HXR flux.

The obtained results are discussed from point of view of their possible diagnostical applications. Title: On the Total Emissivity in Chromospheric Lines in the 17th May 2002 Flare Authors: Prosecky, T.; Kotrc, P.; Kashapova, L. K. Bibcode: 2008ESPM...12.2.63P Altcode: Energy balance in the 17th May 2002 flare was studied. Chromospheric lines observed by the Ondrejov spectrograph were analysed taking into account the HXR data from RHESSI. Positions of the HXR sources were identified at the H-alpha slit-jaw images and the corresponding flare spectra were processed. Total emissivity in H-alpha and H-beta lines was derived and the net energy emitted in these lines during various phases of the flare was estimated. The results were compared with evolution of HXR flux and plasma parameters obtained from the HXR spectra. Title: On Energy Transport Scenarios in the 17th May 2002 Near-limb Flare Authors: Kotrc, P.; Kashapova, L. K.; Frolova, A. S.; Kuprjakov, A. Yu. Bibcode: 2008ESPM...12.2.62K Altcode: We present a reconstruction of the energy transport scenario based on the simultaneous observations in a wide range of electromagnetic spectrum. Particularly, the high-temporal resolution optical and radio spectra from the Ondrejov observatory, data obtained by RHESSI, Nobeyama Radio Observatory, Radio Solar Telescope Network (RSTN), Siberian Solar Radio Telescope (SSRT) and SOHO (MDI and EIT) were analysed to obtain a complex view on the event. Especial attention was payed to the role of accelerated particles in the energy transport and to the excitation mechanisms in different kernels of the flare. As follows from the microwave data the maximum of emission at 17 GHz evolved from the eastern part of the flare to the western one. On chromospheric level the flare consisted of two eruptive centers - eastern and western ones. While the eastern center consisted from a single H? kernel, the western one was rather a complex structure. These centers were associated with different HXR sources. It is worth to note that the western center was connected with a more mighty HXR source of 25-100 keV.

We studied a correlation of the hard X-rays, radio emission and the Balmer series lines for the western center. Probable agents and scenarios of the energy transport as well as possible diagnostic aspects of the results are briefly discussed. Title: Multi-wavelength investigation of energy release and transport in the 16 August 2004 flare Authors: Kashapova, L. K.; Zharkova, V. V.; Grechnev, V. V.; Ipson, S. S. Bibcode: 2008IAUS..247..222K Altcode: 2007IAUS..247..222K The current contribution investigates the solar flare of 16th August 2004 with the multi-wavelength observations with high temporal resolution from RHESSI, Large Solar Vacuum Telescope (LSVT), Hiraiso Solar observatory, Nobeyama Radioheliograph (NoRH, 17 and 34 GHz) and Siberian Solar Radio Telescope (SSRT, 5.7 GHz), TRACE. The main flare was preceded by a pre-flare event with a very short energy release time. The observations of the main flare reveal a close temporal correlation between the Hα intensity observed with LSVT and those in hard and soft X-ray emissions observed with RHESSI, and in microwave fluxes observed with NoRH and SSRT. This close temporal correlation can be only associated with high-energy particles. The role of energetic particles in energy transport and non-thermal excitation and ionisation on Hα emission during the pre-flare and pre-flare event is investigated with full non-LTE approach and possible agents and scenarios of energy transport are discussed. Title: Balmer-Line Diagnostics of Accelerated Particles Authors: Kashapova, L. K.; Kotrč, P.; Kupryakov, Yu. A. Bibcode: 2007ASPC..368..431K Altcode: Preliminary results of empirical study of a non-thermal electron effect on Hα/Hβ line intensity ratio in solar flares are presented. Analysis of spectral observations of the 26 June 1999 flare revealed some peculiarities of the Hα/Hβ line intensity ratio (the ``sidelobes'') in the emission kernels associated with radio bursts and HXR emission that could be considered as an indirect evidence of accelerated non-thermal particle beams. According to our conclusions they appeared due to non-thermal electron beam effects. Consequently, the obtained results confirmed the theoretical predictions and bore a first witness for a detection of the spatial and temporal presence or absence of the non-thermal electron beams in optical spectra. However, as a more statistically probative evidence was needed, we extended our analysis on two flares where presence of non-thermal mechanisms of excitation was verified by HXR data. The obtained results are quite promising as concerns of diagnostics of the energy release and transfer mechanisms during the flare. Title: Signatures of High-Energy Particles in Hα Emission Before the Solar Flare of August 16, 2004 Authors: Kashapova, L. K.; Zharkova, V. V.; Grechnev, V. V. Bibcode: 2007ASPC..368..437K Altcode: We study multi-spectral chromospheric and coronal emissions that appeared during the impulsive event occurring before the flare on 16 August 2004 observed by RHESSI, Large Solar Vacuum Telescope (Irkutsk), and Nobeyama Radioheliograph (NoRH, 17 and 34 GHz). There are three separate sources detected: 1 in hard X-rays (RHESSI), two in microwaves (NoRH) (1 of which coincides with HXR) and one in Hα emission (3). The emission in all sources reveals a close (within 1 s) temporal correlation that can be only associated with precipitation of high-energy particles. Possible scenarios of particle precipitation and its effect on the observed signatures are discussed. Title: The multi-wavelength study of the effect of energetic particle beams on the chromospheric emission in the 25th July 2004 solar flare Authors: Zharkova, V. V.; Kashapova, L. K.; Chornogor, S. N.; Andriyenko, O. V. Bibcode: 2007AdSpR..39.1483Z Altcode: We present the multi-wavelength study of short-term variations of Hα line emission located in multiple kernels on the both sides from magnetic neutral line in the 25th July 2004 solar flare observed by VTT (Tenerife). The HXR and Hα emission in the kernels 1 and 3 is close spatially and temporally while in kernels 4 and 7 there is only delayed Hα emission observed tens seconds after HXR in the kernels 1 and 3. The locations of Hα kernels 1, 3, 4 and 7 are on the opposite sides from the magnetic neutral line. The temporal variations of Hα emission in kernels 1 and 3 coincide within 5 s with the HXR photon emission. The latter is found to have double power law photon spectra, which were corrected to a single power law with the turning point technique accounting for Ohmic losses and collisions. The Hα emission is fit by full non-LTE simulations in an atmosphere heated by an electron beam with the parameters derived from the HXR emission. The combination of radiative, thermal and non-thermal mechanisms of excitation and ionization of hydrogen atoms is considered. The temporal evolution of simulated Hα emission in the kernel 3 fits rather well the two observed intensity increases: the first at the flare onset (13:38:39-13:39:30 UT) caused by pure non-thermal excitation by beam electrons and the second one appearing after 13:40:00 UT because of a hydrodynamic heating. The observed close temporal correlation or delay of Hα emission with HXR emission points out to the precipitation either of electron (kernels 1 and 3) or protons (4 and 7). Title: On the thermal and non-thermal excitation effects as studied in the H[alpha], H[beta] and Ca II 8542 Å line profiles in a solar flare Authors: Kotrč, P.; Kashapova, L. K. Bibcode: 2007msfa.conf..277K Altcode: Spectral observations of the 26 June 1999 flare (Kotrč et al. 2004) presented a unique opportunity to compare effects of thermal and non-thermal mechanisms of excitation on profiles of Balmer series and Ca II 8542 A lines. The radio spectra and HXR flux demonstrated indirect evidence of the non-thermal beam effect on the chromosphere during the flare (Kashapova et al. 2005). We compared the line profiles in the flare kernel associated with the influence of non-thermal electron beams with the "only thermal" kernels. Results are discussed both from their observational and theoretical aspects. Title: Signatures of High Energy Particle Beams in the Chromospheric Events Before the 25 July 2004 Flare Onset Authors: Kashapova, L. K.; Zharkova, V. V.; Chornogo, S. N.; Kotrc, P. Bibcode: 2006IAUJD...1E..47K Altcode: A role of particle beams is studied in the origin and evolution of small-scale chromospheric events appeared before the main phase onset at 13:37 UT of the July 25, 2004 flare. The main goal of our investigation was to detect possible locations of energy release and to trace the processes of energy transport by high-energy particles to the chromosphere. Based on the plasma and beam parameters deduced from hard X-ray flux and UV data, 1D hydrodynamic responses of the atmosphere is calculated and used for a full non-LTE simulation of hydrogen H-alpha line emission taking into account thermal and non-thermal processes. Theoretical line profiles are compared with the observed dynamics of H-alpha intensity. A comparison is carried out of the high energy particle parameters deduced from chromospheric emission, hard X-ray flux and UV data that allows us to find a possible scenario of the event evolution. Title: On Possible Manifestation of Non-Thermal Electrons in the Hα/Hβ Line Profile Ratio in the June 26, 1999 Flare Authors: Kotrc, P.; Kashapova, L. K. Bibcode: 2006IAUJD...1E..46K Altcode: We analyzed the solar flare on 26 June 1999 which consisted of three subsequent phases. All of them were followed by events of quite different types (Kotrc et al., IAU Symp 223, 2004). Just the second phase of the flare was accompanied by radio bursts and HXR emission that could be considered as an indirect evidence of accelerated non-thermal particle beams. Theoretical calculations of thermal mechanisms coupled with accelerated electron beams in flares showed that the ratio of the Hα/Hβ line profiles could be a possible indicator whether a mechanism of non-thermal radiation excitation was present or absent (Kasparova & Heinzel, A&A, 2002). This effect should follow the occurrence of the particle beams in time and then decay. In the flare kernel associated thus possibly with the influence of non-thermal electron beams we found that the ratio of the Hα/Hβ line profiles demonstrated a very specific form which substantially differs from those ones obtained in "thermal" kernels (occurring in the first and in the another flare phases). This effect can be characterized by presence of specific "sidelobes" occurring in the ratio of the line profiles. The effect was observed in the region nearby the HXR sourcelocation where it appeared just after the end of the radio-spectrum spike and therefore it corresponds most probably to the occurrence of non-thermal processes in the flare. The associated HXR effect was rather short lasting, i.e. the effect of "sidelobes" disappeared earlier then the emission. We try to trace the evolution and the possible decay of this effect. On one hand the obtained results will be an additional evidence of the theoretical predictions, on the other hand they could be useful for development of technique for detecting the presence or absence of the non-thermal electron beams. Conclusions are discussed both from their observational and theoretical aspects. Title: The evolution of Hα and CaII K emission before and during the solar M-class flare on 25th July 2004 Authors: Chornogor, S. N.; Kashapova, L. K.; Andriyenko, O. V. Bibcode: 2006IAUS..233..122C Altcode: The last decade observations revealed the essential variations of energy balance take place in the pre-flare active regions at all atmospheric levels and they are caused by both evolution of AR and processes associated with flare activity. We present the multi-wavelength study of the solar flare jointly with the preceding event. The combined investigation is perspective for the mechanism understanding of the energy storage, trigger and release during the solar flares. A special attention was given to signatures of energetic particle beam effect on chromosphere according to Hα and CaII K intensity changes. Combination of data from ground based instruments and space observatories (TRACE, MDI, RHESSI) will allow us to track processes taking place in a wide range of solar atmosphere layers - from the temperature minimum region to the corona. The obtained results are discussed. Title: Investigation of pre-flare role of Ellerman bombs in solar active regions Authors: Papernaya, Yu. V.; Kashapova, L. K. Bibcode: 2006IAUS..233..181P Altcode: Ellerman bombs or moustache are known as short-living fine emission structures associated with a local energy release in solar atmosphere. The relation between the moustaches and flare has been discussed since the moment of the moustaches discovery. The resent results of the Flare Genesis Experiment demonstrated that this problem is still actual and attractive. We took into account the possibility of different mechanisms of their origin (thermal and non-thermal) by using spectro polarimetric data obtained in summer 1999 and carried out analysis of Ellerman bomb's role in flare activity of the Sun by the example of the several active regions. Title: The multi-wavelength study of the effect of energetic particle beams on the chromospheric emission in the 20th and 25th July 2004 solar flares Authors: Zharkova, V. V.; Andriyenko, O. V.; Chornogor, S. N.; Kashapova, L. K.; Sych, R. A. Bibcode: 2006cosp...36.2256Z Altcode: 2006cosp.meet.2256Z We present the results of a multi-wavelength study of short-term variations of H-alpha and CaII K line emission in the 20th and 25th July 2004 solar flares In both flares the fast changes of H-alpha and CaII K intensity observed from VTT correlated very closely seconds with the HXR emission observed by RHESSI that is considered as the signatures of energetic particle beams in the chromosphere For interpretation of the observed emission the full non-LTE radiative simulations were carried out for a combination of radiative thermal and non-thermal mechanisms of excitation and ionization of the hydrogen and Ca emission in flaring atmospheres Various theoretical models are compared with the observational results in order to define the best fits and to clarify the processes of energy transport within a short timescale of seconds from upper to lower atmospheric levels in the solar flares Title: On AN Effect of Particle Beams on Correlation Between Balmer Series Lines Authors: Kashapova, L. K.; Kotrč, P.; Kupryakov, Yu. A.; Kašparová, J. Bibcode: 2005ESASP.600E.126K Altcode: 2005dysu.confE.126K; 2005ESPM...11..126K No abstract at ADS Title: Preflare HXR and Chromospheric Line Emission in NOAA 0652 ON 25TH July 2004 Authors: Chornogor, S. N.; Kashapova, L. K.; Sych, R. A.; Andriyenko, O. V. Bibcode: 2005ESASP.600E.115C Altcode: 2005dysu.confE.115C; 2005ESPM...11..115C No abstract at ADS Title: The viewing angle effect on Hα-line impact polarisation in impulsive solar events Authors: Zharkova, V. V.; Kashapova, L. K. Bibcode: 2005A&A...431.1075Z Altcode: The effect of a viewing angle on the hydroden Hα-line impact polarisation is investigated in a plane vertical atmosphere arbitrary located on the solar disk. The impact polarisation is assumed to be caused by precipitating beam electrons with pitch-angular anisotropy steadily injected into the flaring atmosphere from its top. The polarisation is calculated for a 3 level plus continuum hydrogen atom affected by Zeeman splitting in a moderate magnetic field taking into account depolarising effects of diffusive radiation and collisions with thermal electrons. The Hα polarisation profiles are affected by electron beams only in the line cores whereas the wings are fully depolarized by the collisions with thermal electrons despite the extended wing emission, or “moustaches”, caused by beam electrons. The full (integrated in wavelength) Hα-line linear polarisation, caused by moderate electron beams, is shown to be 2{-}20% and either negative or positive depending on the position of a flaring loop on the solar disk and the direction of an emitted photon from the local magnetic field. The polarisation plane is projected onto a viewing angle psi, being a superposition of the flare location on a solar disk and the magnetic field deviation from vertical on the solar surface. For viewing angles less then 50^circ the Hα-line impact polarisation is negative increasing up to -10% towards smaller angles, meaning that the polarisation is mostly perpendicular to the plane {B}× {K} where B is the magnetic field induction and K is the photon momentum vector. For viewing angles greater than 60^circ the measured impact polarisation becomes positive, sharply increasing up to 20% towards the limb. In the range of 50{-}60^circ the observed impact polarisation goes through a zero point despite the actual presence of beam electrons in the flaring atmosphere. The theoretical predictions of the dependence of polarisation degree on viewing angle fit remarkably well the observations of Hα-line linear polarisation in small-scale flaring events such as moustaches or Ellerman bombs, located in different positions on a solar disk. Title: Transfer of energy within coronal bright points according to the observation in optical spectra and microwave Authors: Prosovetsky, D. V.; Kashapova, L. K. Bibcode: 2004IAUS..223..479P Altcode: 2005IAUS..223..479P The paper is devoted to the coronal bright points. We carried out the analysis of the simultaneous observations in IR He λ10830 Å and microwaves at 5.2 and 1.76 cm. It was obtained that microwave sources correspond to the dark points in IR He λ10830 Å with line-of-sight velocities directed from a observer. The possible mechanism of the energy transport within the bright points are suggested. Title: On the presence of linear polarization in the flare on 26 June, 1999 Authors: Kotrc, P.; Kashapova, L. K.; Kupryakov, J. A. Bibcode: 2004IAUS..223..463K Altcode: 2005IAUS..223..463K Solar flare on 26 June 1999 was accompanied by radio bursts giving an indirect evidence of accelerated superthermal particle beams. It is generally believed that this effect can stimulate an impact linear polarization in Balmer series spectral lines. The flare was observed simultaneously by the Ondrejov Multichannel Flare Spectrograph (MFS) and by the Large Solar Vacuum Telescope (LSVT) using the polarization optics in the Halpha line. Spectropolarimetric data obtained by the two instruments are analyzed, however no substantial linear polarization was detected. Both spectral and auxiliary data, including radio and X-ray observations are analyzed to discuss possible reasons of the lack of linear polarization. Title: Polarization of Ellerman bombs and the arch structure of active region: some results of investigation Authors: Kashapova, L. K. Bibcode: 2004IAUS..223..459K Altcode: 2005IAUS..223..459K The comparison of the polarization presence in Ellerman bombs or moustaches and the active region arch structure was carried out. In the most cases of the polarization, interpreted as impact polarization, were detected in that regions where the bright small loops were observed. On the contrary, when a significant polarization wasn't detected the scanning during observation was carried out nearby the large loops. Title: Spectropolarimetric Investigation of Hα Line Profiles in Moustaches Authors: Kashapova, L. K. Bibcode: 2003ASPC..307..474K Altcode: No abstract at ADS Title: Some results of the spectropolarimetric investigation of Ellerman bombs Authors: Kashapova, L. K. Bibcode: 2002ESASP.506..661K Altcode: 2002svco.conf..661K; 2002ESPM...10..661K Ellerman bombs (EB) or moustaches are enigmatic phenomena of solar atmosphere and mechanisms of their excitation are still unclear. There are two main models of their explanation. Thermal model implies the compression and heating of small regions of solar atmosphere. According to the non-thermal model the beams of energetic particles are considered as the source of EB origin. If the EB have thermal origin, then there is a large possibility that they will show a prominent center-to limb variation of the Hα line profiles. The Hα line polarization would be about 2-3% both in the line core and in the wings. The moustaches arisen as the result of bombardment by energetic particle beams will show a polarization observed in the Hα line core only. The form of these Hα line profiles would correlate with their life time. The contribution presents an investigation of the Hα line profiles in EB which showed the polarization of different types. We also make an attempt to analyse correlation between the life time and the form of the Hα line profiles obtained for three long-living moustaches, which showed significant linear polarization in the line core. Title: Measurement and processing of linear polarization in solar flares - a comparison of two methods Authors: Kotrč, P.; Firstova, N. M.; Kashapova, L. K.; Kupryakov, Yu. A. Bibcode: 2002ESASP.506..947K Altcode: 2002svco.conf..947K; 2002ESPM...10..947K Linear polarization measurement in solar flares is discussed from the point of view of the processing technique. Usually, spectropolarimetric investigation of the linear polarization in solar flares is carried out for the line profiles. The results obtained by two methods (either processing of individual profiles or the whole spectral strips) are compared and applied to the observations obtained at the Large Solar Vacuum Telescope (the Baikal Astrophysial obseratory) and at the Ondřejov Multichannel Flare Spectrograph. The results obtained by the second method are comparable by accuracy with the results obtained by the first one. Moreover, it allows to check the instrumental polarization and the polarization behaviour in the nearby objects. However, the profile operating method allows to investigate the polarization effects along the dispersion more carefully. Title: On the possible manifestation of the solar G-mode in the Earth atmosphere Authors: Klochek, N. V.; Nikonova, M. V.; Kashapova, L. K.; Sotnikova, R. T. Bibcode: 2002ESASP.506..153K Altcode: 2002ESPM...10..153K; 2002svco.conf..153K The Sun influences the processes occurred in the Earth's atmosphere and interplanetary space by means of not only electromagnetic but presumably gravitational forces. As it was reported by a group of researches (Thomson, D. et al.) charged particles in the interplanetary medium reveal variations with periods approaching theoretically expected periods of solar g-modes. It is believed that the detected periodicities are an indirect manifestation of these modes. Special attention was paid to the quasi-two-day periodicity of 2.2 days. To investigate its origin these authors carried out an analysis of atmospheric pressure variations which reveals the 2.2 day periodicity. We are justified in anticipating a manifestation of characteristic properties of this periodicity in space and in time. The wave process in the Earth's atmosphere with a typical quasi-two-day period reveals the quadrupole structure which seems to be the response to the effect of the low-frequency g-mode of the Sun. Title: A Spectropolarimetric Study of Ellerman Bombs Authors: Kashapova, L. K. Bibcode: 2002ARep...46..918K Altcode: We have studied four 10 to 40 minute sets of Hα spectropolarimetric observations of five Ellerman bombs (a total of 241 spectropolarimetric recordings) selected from data for more than 200 Ellerman bombs obtained with the Large Solar Vacuum Telescope at the Ba kal Astrophysical Observatory. The degree of polarization P and azimuth of the plane of polarization were derived from quasi-simultaneous observations of the Stokes parameters Q/I and U/I. We interpret the observed linear polarization as impact polarization. A method for comparing the polarization parameters of Ellerman bombs observed at different times and distances from the center of the solar disk is suggested, which can be used to relate variations of the polarimetric parameters with the lifetimes of Ellerman bombs. A comparison between the observations and theoretical calculations indicates that the observed Ellerman bombs were due to electron beams with energies of several hundred keV. Title: Observation of the linear polarization in the flare with a powerful surge Authors: Firstova, N. M.; Kashapova, L. K. Bibcode: 2002A&A...388L..17F Altcode: An investigation of the linear polarization in the flare with a powerful surge revealed an unusual behavior of the Stokes parameter profiles along the dispersion. We discuss the probability that photons propagating from the flare and passing through the surge generate a linearly polarized radiation of the surge. Title: The results of spectropolarimetric observations of solar flares followed by surge Authors: Firstova, N. M.; Kashapova, L. K. Bibcode: 2002ESASP.477..103F Altcode: 2002scsw.conf..103F An investigation of the linear polarization in the June 29, 1999 flare with a powerful surge (the maximum velocity was about 160 km/sec) revealed an unusual behavior of the Stokes parameter profiles along the dispersion. We discuss the probability that photons propagating from the flare and passing through the surge generate a linearly polarized radiation of the surge. Title: Investigation of He I 10 830 Å `Dark Points' at the Sayan Solar Observatory and the Baikal Astrophysical Observatory Authors: Skomorovsky, V. I.; Firstova, N. M.; Kashapova, L. K.; Kushtal, G. I.; Boulatov, A. V. Bibcode: 2001SoPh..199...37S Altcode: A new two-bandpass birefringent filter has been produced at ISTP, Irkutsk for the investigation of the fine structure of the chromosphere. One filter passband is centered on the He i 10 830 Å line, the second one is centered on Hα. The FWHM of the He i 10 830 Å passband is 0.46 Å and of the Hα passband is 0.3 Å. A large number of filtergrams were obtained with the filter at the Sayan observatory. At the same time, spectral observations with high spatial and spectral resolution were carried out by the large solar vacuum telescope at the Baikal Observatory. We selected 29 `dark point' spectra with sizes from 2'' to 13'', as well as `dark points' on the filtergrams. Comparison of spectrograms and filtergrams has shown a good agreement of their size and intensity in relation with the surrounding chromosphere as well as the absence of primary line-of-sight velocities in both observation types. From spectral observations, the depth of 10 830 Å is over 30% for some `dark points', and the FWHM is more than 1 Å. He i 10 830 Å line profiles in `dark points' are more deep and wide than in quiet regions. The optical depth of the chromosphere in `dark points' is estimated. Comparison with the unperturbed chromosphere showed that `dark points' in He i 10 830 Å are more optically thin than the nearby chromosphere. Title: The Today's Investigations on Large Solar Vacuum Telescope Authors: Skomorovsky, V. I.; Firstova, N. M.; Kashapova, L. K.; Firstova, A. V.; Kushtal, G. I. Bibcode: 2001AGM....18.P221S Altcode: The contribution presents the prospective observations obtained with the Large Solar Vacuum Telescope (Baikal astrophysical observatory, Irkutsk) from 1997 after its re-equipment by CCD-camera. During the latest years we carried out basically the spectropolarimetric Hα observations of the emission objects of different sizes from the solar flares to the Ellerman bombs. The flares followed by a surges have aroused a special interest. The observations and preliminary results are shown. The Ellerman bombs or moustaches were devoted much attention. We obtained the extensive observational data( more than 200 objects) and the various mechanisms of their arising have been analyzed. Besides the investigation of the linear polarization in Hα line the spectral observations in IR region (HeI 10830 Å line) were carried out. Also we obtain the observation of the pores in the several Fe lines for the latest two years. This work was supported by Russian Foundation for Basic Research grants 00-02-16068-a and 01-02-06203. Thanks are also due the State Support of Leading Scientific Schools of the Russian Federation grant 00-15-96659 and the State Scientific and Technical Program ``Astronomy'' for their support. Title: Program for the 1999 August 11 eclipse Authors: Grigoriev, V. M.; Eselevich, V. G.; Kashapova, L. K.; Salakhutdinov, R. T.; Skomorovsky, V. I. Bibcode: 1999CoSka..28..256G Altcode: A study of the solar coronal fine structure up to 5--6 solar radii as an indicator of the global and local processes on the Sun. The experimental detection of fast changes in coronal structures. An investigation of the minimal and maximal coronal structure (streamer form) as a result of the plasma layer projection on the picture plane along the neutral line. Obtaining 8--10 images of the white-light corona with the radial neutral filter. The special telescope was developed and manufactured. The telescope tube is directed to (or from) the polar star. The Sun's tracking is carried out by the whole telescope tube with the heliostat mirror around the polar axis. The lens of the telescope is a two-component Petzval type, the diameter is 120 mm, and the focal length is 1200 mm. The assumed angular resolution at the region +/-2.5 degree is near 5 arcsec. Data will be recorded either via an automatic 8-cm aerial camera or using a CCD-detector. Title: The linear polarization in moustaches Authors: Firstova, N. M.; Boulatov, A. V.; Kashapova, L. K. Bibcode: 1999ASSL..243..451F Altcode: 1999sopo.conf..451F No abstract at ADS Title: A spectropolarimetric study of the Hα radiation from Ellerman bombs. Authors: Kazantsev, S. A.; Firstova, N. M.; Kashapova, L. K.; Bulatov, A. V.; Petrashen', A. G. Bibcode: 1998RuPhJ..41.1258K Altcode: Polarization data are given for three whiskers recorded with the large solar vacuum telescope at Baikal Observatory, Institute of Solar-Terrestrial Physics, Russian Academy of Sciences. The observed degree of polarization varies from 2 to 13%. The direction of the polarization plane for the medium intensity whisker was tangential, while that for the weakest one was radial. The brightest whisker had a polarization plane direction close to radial at the center of the line but tangential at the flanks. It is assumed that the polarization is due to impact excitation of a hydrogen-atom ensemble in the solar chromosphere by an electron beam, and estimates are made of the beam energy. Title: Spectropolarimetric studies of H alpha emission in "solar moustaches": Observations and calculation of the Stokes parameters Authors: Kazantsev, S. A.; Firstova, N. M.; Kashapova, L. K.; Bulatov, A. V.; Petrashen', A. G.; Henoux, J. -C. Bibcode: 1998ARep...42..702K Altcode: The results of spectropolarimetric observations of three solar `moustaches' carried out on the Large Vacuum Solar Telescope of Baikal Observatory of the Institute of Solar-Terrestrial Physics are presented. The observed degree of polarization varies from 2-13%. The direction of the plane of polarization for a moustache with moderate intensity is tangential, and is radial for the weakest moustache. In the brightest moustache, the plane of polarization is close to radial at the line center, and is tangential in the wings. Title: A program of Observations for the August 11, 1999 Total Solar Eclipse Authors: Grigoriev, V. M.; Eselevich, V. G.; Kashapova, L. K.; Salakhutdinov, R. T.; Skomorovsky, V. I. Bibcode: 1998jena.conf...12G Altcode: A study of the solar coronal fine structure up to 5--6 solar radii as an indicator of the global and local processes on the Sun. The experimental detection of fast changes in coronal structures. An investigation of the minimal and maximal coronal structure (streamer form) as a result of the plasma layer projection on the picture plane along the neutral line. Obtaining 8--10 images of the white-light corona with the radial neutral filter. The special telescope was developed and manufactured. The telescope tube is directed to (or from) the polar star. The Sun's tracking is carried out by the whole telescope tube with the heliostat mirror around the polar axis. The lens of the telescope is a two-component Petzval type, the diameter is 120 mm, and the focal length is 1200 mm. The assumed angular resolution at the region ±2.5 degree is near 5 arcsec. Data will be recorded either via an automatic 8-cm aerial camera or using a CCD-detector. Title: Image Processing of Digitized Spectral Data Authors: Boulatov, A. V.; Kashapova, L. K. Bibcode: 1998ASPC..145...63B Altcode: 1998adass...7...63B Every observatory has a library of old pictures taken by photographic cameras. These measurements are not as such high quality as those from modern CCD systems, but could contain important data about rare phenomena or source data for long-period investigations (e.g., concerning the solar cycle). This paper presents methods for converting photographic images, collected at the Large Solar Vacuum Telescope (Baikal Astrophysical Observatory) to digital images, similar to CCD pictures. Special algorithms were used for this task and have been implemented in the IDL environment. The results of processing real spectral data and a comparison of processed photographic images and images taken with a TEK CCD are presented.