Author name code: ren
ADS astronomy entries on 2022-09-14
author:"Ren, Deqing"
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Title: A high-speed and high-efficiency imaging polarimeter based
on ferroelectric liquid crystal retarders: Design and test
Authors: Guo, Jing; Ren, Deqing; Zhu, Yongtian; Zhang, Xi
Bibcode: 2021PASJ...73..405G
Altcode: 2021PASJ..tmp...19G
Polarimeters play a key role in investigating solar magnetic fields. In
this paper, a High speed and high efficiency Imaging POlarimeter
(HIPO) is proposed based on a pair of ferroelectric liquid crystal
retarders (FLCs), with the ultimate goal of measuring magnetic
fields of prominences and filaments from the ground. A unique
feature of the HIPO is that it enables high cadence polarization
measurements covering a wide field of view (FOV); the modulation
frequency of the HIPO is able to achieve ∼100 Hz, which greatly
suppresses the seeing-induced crosstalk, and the maximum FOV can reach
62″ × 525″. Additionally, FLC retardances
under low and high states were calibrated individually and found to
have a slight discrepancy, which is neglected in most works. Based
on FLC calibration results, an optimization was performed using a
constrained nonlinear minimization approach to obtain the maximum
polarimetric efficiency. Specifically, optimized efficiencies of the
Stokes Q, U, and V are well balanced and determined as (ξQ,
ξU, ξV) = (0.5957, 0.5534, 0.5777), yielding a
total efficiency of 0.9974. Their practical efficiencies are measured as
(ξQ', ξU', ξV') = (0.5934, 0.5385,
0.5747), slightly below the optimized values but still resulting
in a high total efficiency of 0.9861. The HIPO shows advantages in
terms of modulation frequency and polarimetric efficiency compared
with most other representative ground-based solar polarimeters. In
the observations, measurement accuracy is found to be better than 2.7
× 10-3 by evaluating full Stokes Hα polarimetry results
of the chromosphere. This work lays a foundation for the development
of high-speed and high-accuracy polarimeters for our next-generation
solar instruments.
Title: Global optimization-based reference star differential imaging
for high-contrast exoplanet imaging survey
Authors: Ren, Deqing; Chen, Yili
Bibcode: 2021MNRAS.502.2158R
Altcode: 2021MNRAS.tmp...64R
We propose a data reduction approach called global optimization-based
reference star differential imaging (G-RDI), which can be used for
exoplanet imaging survey, where large numbers of target stars from
the same young stellar association are imaged and where no field
rotation is needed. One of the unique features of our G-RDI is that
we select reference stars from other scientific target stars in the
same stellar association to optimize for high-contrast imaging with
a target star, which maximizes the observational efficiency and also
delivers good performance to remove the speckle noise so that high
contrast is achievable even at a small inner working angle (IWA) to
the host star of being imaged. We proposed the G-RDI that is optimized
for high-contrast exoplanet imaging at a small IWA and to provide a
contrast that is significantly better than the current reference star
differential imaging (RDI) method. In addition, we also propose the
use of multiple reference stars and found that our G-RDI can further
deliver better performance in that case. The result was compared with
other exoplanet data reduction techniques, including the traditional
RDI, and it indicated that our G-RDI with two reference stars can
significantly improve the contrast performance at a small IWA with
a high observational efficiency - two critical features that current
data reduction techniques cannot offer. This approach could be used
with both equatorial and alt-azimuth mount telescopes, and provides a
new option for future exoplanet imaging surveys with high observational
efficiency at a small IWA.
Title: Persistence of the long-duration daytime TEC enhancements at
different longitudinal sectors during the August 2018 geomagnetic
storm
Authors: Li, Q.; Huang, F.; Zhong, J.; Zhang, R.; Kuai, J.; Lei, J.;
Liu, L.; Ren, D.; Guo, J.; Ma, H.; Yoshikawa, A.; Hu, L.; Cui, J.
Bibcode: 2020AGUFMSA0350013L
Altcode:
In this study, the ionospheric responses around the Asian-Australian,
American, and African sectors during the August 2018 geomagnetic storm
were investigated based on the Beidou GEO satellite and MIT Madrigal
total electron contents (TECs), combined with measurements from
ionosondes, magnetometers, and Global Ultraviolet Imager (GUVI). The
mid and low latitude TECs were dominated by positive responses over
the three longitudinal sectors during the storm on August 26-29. It is
unique that all TECs at the Asian-Australian, American, and African
sectors displayed large daytime enhancements larger than 10 TECu on
August 27-29, during the recovery phase, when the ionosphere is usually
dominated by plasma depletions due to the ionospheric disturbance
dynamo and/or disturbed thermospheric compositions. The combination and
competition of the disturbed vertical plasma drifts through the solar
wind-magnetosphere-ionosphere (SW-M-I) coupling, and disturbed neutral
composition contribute significantly to the daytime TEC responses at
different longitudinal sectors on August 26 during the main and early
recovery phases. The eastward equatorial electrojet and O/N2 are larger
than the quiet reference during the recovery phase on August 27-29,
which suggest the enhanced upward vertical plasma drifts combined with
higher O/N2 make an important contribution on the daytime positive
ionospheric storm during the recovery phase. The enhanced vertical
plasma drifts could not be driven by the SW-M-I coupling or ionospheric
disturbance dynamo associated with geomagnetic storm. Further studies
should be untaken to explore the dominant sources for the enhanced
upward vertical drifts during the recovery phase.
Title: A High-Efficiency and High-Accuracy Polarimeter for Solar
Magnetic Field Measurements
Authors: Ren, Deqing; Han, Zijian; Guo, Jing
Bibcode: 2020SoPh..295..109R
Altcode:
Solar activity is dominated by the magnetic field. Nowadays, a
polarimeter is a mandatory tool to measure solar magnetic fields,
which are generally faint and correspond to a polarization of an
order of 10−2-10−4. As such, polarization
measurements of high efficiency with a high accuracy are crucial to
investigate faint magnetic fields. Here we propose a high-efficiency
and high-accuracy polarimeter, which is based on a pair of nematic
liquid crystal variable retarders (LCVRs) and a Wollaston prism
(WP). It uses a dedicated Stokes modulation strategy to achieve
high efficiency. A calibration unit (CU) is developed to measure the
polarimeter response matrix, which provides a high-precision calibration
to correct possible systematic errors. Compared with other traditional
polarimeters, the modulation scheme of our polarimeter is flexible. In
addition to be able to measure all the three Stokes polarization
components (Q , U , or V ) simultaneously, it can also measure one
or two of these polarization components alone, with high polarization
efficiency. Dedicated alignment and calibration techniques optimized
for our polarimeter are developed and high measurement accuracy is
achieved. In our laboratory experimental test, our two-image based
polarization measurement delivers an overall measurement accuracy
of the order of 10−4, which is about 10 times better,
compared with our previous polarimeters that use the traditional
four-image polarization modulation. This work provides a new option
for high-efficiency and high-accuracy polarization measurement for
future solar synoptic observations.
Title: A low-cost and duplicable portable solar adaptive optics
system based on LabVIEW hybrid programming
Authors: Ren, Deqing; Wang, Gang
Bibcode: 2020PASJ...72...30R
Altcode:
We have developed a portable solar adaptive optics (PSAO) for
diffraction-limited imaging based on today's multi-core personal
computer. Our PSAO software is written in LabVIEW code, which features
block-diagram function based programming and can dramatically speed
up the software development. The PSAO can achieve a ~1000 Hz open-loop
correction speed with a Shack-Hartmann Wave-front Sensor (SH-WFS) in 11
× 11 sub-aperture configuration. The image shift measurements for solar
wave-front sensing are the most time-consuming computations in a solar
adaptive optics (AO) system. Since our current LabVIEW program does not
fully support multi-core techniques for the image shift measurements,
it cannot fully take advantage of the multi-core computer's power for
parallel computation. In order to accelerate the AO system's running
speed, a dedicated message passing interface/open multi-processing
parallel programming technique is developed for our LabVIEW-based
AO program, which fully supports multi-core parallel computation
in LabVIEW programming. Our experiments demonstrate that the hybrid
parallel technique can significantly improve the running speed of the
solar AO system, and this work paves the way for the applications of
a low-cost and duplicable PSAO system for large solar telescopes.
Title: A Host-star Calibration Based Polarimeter for Earth-like
Exoplanet Imaging
Authors: Ren, Deqing; Ranganathan, Mohanakrishna; Christian, Damian J.
Bibcode: 2019PASP..131k5004R
Altcode:
We propose a polarimeter, which is dedicated to Earth-like
exoplanet imaging for future space missions. We adopt a
minimum-polarization-component design philosophy, which makes a
compact and robust system as well as high-performance achievable
in the real world. Our polarimeter consists of two polarization
components of a liquid crystal variable retarders (LCVR) and a
Wollaston prism. The polarimeter can deliver an extra contrast
better than 10-4.5. Combined with one of the currently
available coronagraphs that are delivering a contrast on the order of
10-6.5, the coronagraph and polarimeter system can deliver a
contrast better than 10-11 at a small inner working angle in
the visible over the entire imaging plane. We discuss the polarimeter
design concept and dedicated data-reduction technique. Our unique
host-star calibration algorithm allows the starlight to be totally
removed, regardless of whether the host-star image is intrinsically
polarized or whether the light is polarized by preoptics, such as the
telescope that is located before the polarimeter, which makes exoplanet
polarization imaging feasible with any telescope, optical system, and
target star. Using minimum-polarization components with a solid-state
image LCVR as the key polarization component, our polarimeter is
less sensitive to the wavefront phase and amplitude errors than
other exoplanet imaging techniques. Based on commercial-grade optical
components, we demonstrated for the first time that by combining our
polarimeter with a currently available coronagraph, the polarimeter and
coronagraph system can deliver a contrast better than 10-11
at a small inner working angle in the visible wavelengths, which paves
the way for Earth-like exoplanet imaging for a future space mission.
Title: Numerical Simulation Research of Advanced Multiple Aperture
Seeing Profiler
Authors: Yang, F.; Zhao, G.; Ren, D. Q.
Bibcode: 2019AcASn..60...51Y
Altcode:
The Advanced Multiple Aperture Seeing Profiler (A-MASP) consists
of two small telescopes, and it could measure the daytime turbulence
profile by observing the granulation of the solar surface. The advanced
formula used to measure the turbulence profile could eliminate the
relative pointing error between the two telescopes. The method of
numerical simulation is used to study the detection performance
of this instrument. The A-MASP is insensitive to turbulence near
the earth's surface after the calculation formula of turbulence
profile for eliminating jitter is used. When the distance of the two
telescopes is 0.4 meter, turbulence below 400 meters could not be
measured. In A-MASP, the sample height is not uniform, which will
cause the distortion of the measurement result. Thus a method for
calculating the equivalent sampling height is proposed, which could
correct this distortion effectively. 100 layers of phase screens were
used to simulate the atmospheric turbulence profile. The results show
that when the distance of the telescopes is different, the results
of turbulent profile measurements have their own focuses. When the
distance is relatively close (0.4 m), A-MASP has a high accuracy for
measuring the turbulence profile from 0.4 km to 5 km. When the distance
is 1.2 meters and 2.0 meters, the measurement of turbulence profile
above 5 km is more accurate. Turbulent profiles could be obtained at
different heights by changing the distance of the telescopes.
Title: The First Solar Seeing Profile Measurement with Two Apertures
and Multiple Guide Regions
Authors: Ren, Deqing; Zhao, Gang; Wang, Xin; Beck, Christian;
Broadfoot, Robert
Bibcode: 2019SoPh..294....1R
Altcode: 2018SoPh..294....1R
Ground-based observations suffer from atmospheric turbulence
perturbations, which seriously degrade the image quality. The seeing
profile associated with the turbulence is critical to characterize an
astronomical site. The optimal design and performance estimation of
future solar ground-layer adaptive optics (GLAO) and multi-conjugate
adaptive optics (MCAO) heavily rely on our knowledge of the seeing
profile at a specific site. Many current optical seeing profile
measurement techniques require one to use a large solar telescope for
that purpose. The development of a portable instrument to measure and
characterize the seeing profile is thus highly needed, in particular
for testing potential new sites or for the regularly monitoring of
the seeing condition at existing sites. Recently, we proposed the
Advanced Multiple Aperture Seeing Profiler (A-MASP), which uses multiple
small telescopes and multiple regions of interest (ROIs) on the solar
surface to measure the seeing profile up to an altitude of 30 km. Here,
we report our recent proof-of-concept observation run of the A-MASP
technique with the Dunn Solar Telescope (DST) of the National Solar
Observatory (NSO). We found that the Fried parameter, r0, was
about 12 cm at the observed wavelength of 630 nm in the early morning
and that there were three main turbulence layers. The strongest one
was the mix layer near the ground. We observed the evolution of the
top of the mix layer and found that it can rise to about 1.5 km in
about 18 min, which is consistent with the theory of daytime boundary
layer evolution. Another turbulence layer was observed from 8 to 15 km,
which is at the top of the convective layer. Comparing an instrument
with two sub-apertures with a real A-MASP instrument, we found that
they should lead to similar results except for the altitude h =0.
Title: A simulation study of the equatorial ionospheric response to
the October 2013 geomagnetic storm
Authors: Lei, J.; Ren, D.
Bibcode: 2017AGUFMSA34A..06L
Altcode:
The ionospheric observation from ionosonde at Sao Luis (2.5S, 44.2W;
7S dip latitude) around the magnetic equator showed that the nighttime
ionospheric F2 peak height (hmF2) was uplifted by more than 150 km
during the October 2013 geomagnetic storm. The changes of hmF2 at
the magnetic equator were generally attributed to the variations of
vertical drift associated with zonal electric field. In this paper,
the Thermosphere Ionosphere Electrodynamics General Circulation Model
(TIEGCM) simulation results are utilized to explore the possible
physical mechanisms responsible for the observed increase of hmF2 at
Sao Luis. The TIEGCM reproduced the changes of F2 peak electron density
(NmF2) and its height (hmF2) during the main and recovery phases of the
October 2013 storm. A series of controlled simulations revealed that,
besides the enhancement of vertical plasma drift, the convergence of
horizontal neutral winds and thermospheric expansion also contributed
significantly to the profound increase of nighttime hmF2 observed at
Sao Luis on 2 October. Moreover, the changes of neutral winds and
neutral temperature in the equatorial region are associated with
the interference of storm time travelling atmospheric disturbances
originating from high latitudes.
Title: Phase Quantization Study of Spatial Light Modulator for
Extreme High-contrast Imaging
Authors: Dou, Jiangpei; Ren, Deqing
Bibcode: 2016ApJ...832...84D
Altcode: 2016arXiv160904870D
Direct imaging of exoplanets by reflected starlight is extremely
challenging due to the large luminosity ratio to the primary
star. Wave-front control is a critical technique to attenuate the
speckle noise in order to achieve an extremely high contrast. We
present a phase quantization study of a spatial light modulator (SLM)
for wave-front control to meet the contrast requirement of detection
of a terrestrial planet in the habitable zone of a solar-type star. We
perform the numerical simulation by employing the SLM with different
phase accuracy and actuator numbers, which are related to the achievable
contrast. We use an optimization algorithm to solve the quantization
problems that is matched to the controllable phase step of the SLM. Two
optical configurations are discussed with the SLM located before and
after the coronagraph focal plane mask. The simulation result has
constrained the specification for SLM phase accuracy in the above two
optical configurations, which gives us a phase accuracy of 0.4/1000
and 1/1000 waves to achieve a contrast of 10-10. Finally,
we have demonstrated that an SLM with more actuators can deliver a
competitive contrast performance on the order of 10-10
in comparison to that by using a deformable mirror.
Title: Advanced Multiple Aperture Seeing Profiler
Authors: Ren, Deqing; Zhao, Gang
Bibcode: 2016PASP..128j5002R
Altcode:
Measurements of the seeing profile of the atmospheric turbulence
as a function of altitude are crucial for solar astronomical
site characterization, as well as the optimized design and
performance estimation of solar Multi-Conjugate Adaptive Optics
(MCAO). Knowledge of the seeing distribution, up to 30 km, with
a potential new solar observation site, is required for future
solar MCAO developments. Current optical seeing profile measurement
techniques are limited by the need to use a large facility solar
telescope for such seeing profile measurements, which is a serious
limitation on characterizing a site's seeing conditions in terms of
the seeing profile. Based on our previous work, we propose a compact
solar seeing profiler called the Advanced Multiple Aperture Seeing
Profile (A-MASP). A-MASP consists of two small telescopes, each with
a 100 mm aperture. The two small telescopes can be installed on a
commercial computerized tripod to track solar granule structures for
seeing profile measurement. A-MASP is extreme simple and portable,
which makes it an ideal system to bring to a potential new site for
seeing profile measurements.
Title: Feasibility of hydrogen density estimation from tomographic
sensing of Lyman alpha emission
Authors: Waldrop, L.; Kamalabadi, F.; Ren, D.
Bibcode: 2015AGUFMSA32A..07W
Altcode:
In this work, we describe the scientific motivation, basic principles,
and feasibility of a new approach to the estimation of neutral hydrogen
(H) density in the terrestrial exosphere based on the 3-D tomographic
sensing of optically thin H emission at 121.6 nm (Lyman alpha). In
contrast to existing techniques, Lyman alpha tomography allows for
model-independent reconstruction of the underlying H distribution in
support of investigations regarding the origin and time-dependent
evolution of exospheric structure. We quantitatively describe the
trade-off space between the measurement sampling rate, viewing geometry,
and the spatial and temporal resolution of the reconstruction that is
supported by the data. We demonstrate that this approach is feasible
from either earth-orbiting satellites such as the stereoscopic NASA
TWINS mission or from a CubeSat platform along a trans-exosphere
trajectory such as that enabled by the upcoming Exploration Mission
1 launch.
Title: Multiple-Aperture-Based Solar Seeing Profiler
Authors: Ren, Deqing; Zhao, Gang; Zhang, Xi; Dou, Jiangpei; Chen,
Rui; Zhu, Yongtian; Yang, Feng
Bibcode: 2015PASP..127..870R
Altcode:
No abstract at ADS
Title: The Direct Imaging Search of Exoplanets from Ground and Space
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian
Bibcode: 2015IAUGA..2255996D
Altcode:
Exoplanets search is one of the hottest topics in both modern astronomy
and public domain. Until now over 1990 exoplanets have been confirmed
mostly by the indirect radial velocity and transiting approaches,
yielding several important physical information such as masses and
radius. The study of the physics of planet formation and evolution will
focus on giant planets through the direct imaging.However, the direct
imaging of exoplanets remains challenging, due to the large flux ratio
difference and the nearby angular distance. In recent years, the extreme
adaptive optics (Ex-AO) coronagraphic instrumentation has been proposed
and developed on 8-meter class telescopes, which is optimized for the
high-contrast imaging observation from ground, for the giant exoplanets
and other faint stellar companions. Gemini Planet Imager (GPI) has
recently come to its first light, with a development period over 10
years. The contrast level has been pushed to 10-6. Due to the
space limitation or this or other reasons, none professional adaptive
optics is available for most of current 3~4 meter class telescopes,
which will limit its observation power to some extent, especially in the
research of high-contrast imaging of exoplanets.In this presentation,
we will report the latest observation results by using our Extreme
Adaptive Optics (Ex-AO) as a visiting instrument for high-contrast
imaging on ESO’s 3.58-meter NTT telescope at LSO, and on 3.5-meter ARC
telescope at Apache Point Observatory, respectively. It has demonstrated
the Ex-AO can be used for the scientific research of exoplanets and
brown dwarfs. With a update of the currect configuration with critical
hardware, the dedicated instrument called as EDICT for imaging research
of young giant exoplanets will be presented. Meanwhile, we have fully
demonstrated in the lab a contrast on the order of 10-9
in a large detection area, which is a critical technique for future
Earth-like exoplanets imaging space missions. And a space program of
JEEEDIS will also be presented in this talk.
Title: Multiple-Aperture Based Solar Seeing Profiler
Authors: Zhao, Gang; Ren, Deqing
Bibcode: 2015IAUGA..2256161Z
Altcode:
Characterization of daytime atmospheric turbulence profile up to 30 km
above the telescope is crucial for designs and performance estimations
of solar Multi-Conjugate Adaptive Optics (MCAO) systems. To measure
seeing profiles up to 30km, we introduce the Multiple Aperture Seeing
Profiler (MASP). It bases on the principle of S-DIMM+ and consists of
two portable small telescopes similar to SHABAR. Thus the MASP take
the advantages of both S-DIMM+ and SHABAR. It is portable and can be
used without big telescope, while it has ability to measure turbulence
profile up to 30km. Numerical simulations are carried out to evaluate
the performance of MASP. We find that for one layer case, MASP can
retrieve the seeing with error ~5% using 800 frames of WFS data,
which is quite similar with the results of a telescope with diameter
of 1120mm. We also simulate profiles with four turbulence layers, and
find that our MASP can well retrieve the strengths and heights of the
four turbulence layers. Since previous measurements at BBSO showed
that daytime turbulence profile typically consists of four layers,
MASP we introduced is sufficient for actual seeing measurement.
Title: Solar Ground-Layer Adaptive Optics
Authors: Ren, Deqing; Jolissaint, Laurent; Zhang, Xi; Dou, Jianpei;
Chen, Rui; Zhao, Gang; Zhu, Yongtian
Bibcode: 2015PASP..127..469R
Altcode:
No abstract at ADS
Title: A High-contrast Imaging Algorithm: Optimized Image Rotation
and Subtraction
Authors: Dou, Jiangpei; Ren, Deqing; Zhao, Gang; Zhang, Xi; Chen,
Rui; Zhu, Yongtian
Bibcode: 2015ApJ...802...12D
Altcode: 2015arXiv150103893D
Image Rotation and Subtraction (IRS) is a high-contrast imaging
technique that can be used to suppress the speckle noise and facilitate
the direct detection of exoplanets. IRS is different from Angular
Differential Imaging (ADI), in that it will subtract a copy of the image
with 180° rotated around its point-spread function (PSF) center, rather
than the subtraction of the median of all of the PSF images. Since
the planet itself will be rotated to the other side of the PSF, IRS
does not suffer from planet self-subtraction. In this paper, we have
introduced an optimization algorithm to IRS (OIRS), that can provide
an extra contrast gain at small angular separations. The performance
of OIRS has been demonstrated with ADI data. We then made a comparison
of the signal-to-noise ratio (S/N) achieved by algorithms of locally
optimized combinations of images and OIRS. Finally, we found that the
OIRS algorithm can deliver a better S/N for small angular separations.
Title: A coronagraph based on two spatial light modulators for active
amplitude apodizing and phase corrections
Authors: Dou, Jiangpei; Ren, Deqing; Zhang, Xi; Zhu, Yongtian; Zhao,
Gang; Wu, Zhen; Chen, Rui; Liu, Chengchao; Yang, Feng; Yang, Chao
Bibcode: 2014SPIE.9147E..8OD
Altcode:
Almost all high-contrast imaging coronagraphs proposed until now are
based on passive coronagraph optical components. Recently, Ren and Zhu
proposed for the first time a coronagraph that integrates a liquid
crystal array (LCA) for the active pupil apodizing and a deformable
mirror (DM) for the phase corrections. Here, for demonstration
purpose, we present the initial test result of a coronagraphic
system that is based on two liquid crystal spatial light modulators
(SLM). In the system, one SLM is served as active pupil apodizing and
amplitude correction to suppress the diffraction light; another SLM
is used to correct the speckle noise that is caused by the wave-front
distortions. In this way, both amplitude and phase error can be actively
and efficiently compensated. In the test, we use the stochastic parallel
gradient descent (SPGD) algorithm to control two SLMs, which is based on
the point spread function (PSF) sensing and evaluation and optimized for
a maximum contrast in the discovery area. Finally, it has demonstrated
a contrast of 10-6 at an inner working angular distance of
~6.2 λ/D, which is a promising technique to be used for the direct
imaging of young exoplanets on ground-based telescopes.
Title: Period variation and four color light curves investigation
of AB And
Authors: Li, K.; Hu, S. -M.; Jiang, Y. -G.; Chen, X.; Ren, D. -Y.
Bibcode: 2014NewA...30...64L
Altcode:
New determined B, V, R and I light curves of AB And have been analyzed
by the fourth version of the Wilson-Devinney code. This is the first
time to obtain four color light curves of AB And simultaneously. It
is found that AB And is a middle mass ratio W-type contact binary
system with a degree of contact factor f=25.2%±0.2%. One dark
spot on the primary component is introduced to explain the unequal
height of the two maxima. The orbital period investigation based
on all the visual, photographic, photoelectric and CCD times of
light minimum shows that the period of AB And includes a long-term
increase (dP/dt=1.46×10-7 days yr) and an oscillation
(A3=0.121 days; T3=98.3 years). These may be
caused by mass transfer and the light time effect of a third compact
companion.
Title: The first portable solar and stellar adaptive optics
Authors: Ren, Deqing; Li, Rong; Zhang, Xi; Dou, Jiangpei; Zhu,
Yiangtian; Zhao, Gang; Wu, Zhen; Chen, Rui; Liu, Chengchao; Yang,
Feng; Yang, Chao
Bibcode: 2014SPIE.9148E..2WR
Altcode:
We have developed a portable solar and stellar adaptive optics (PSSAO)
system, which is optimized for solar and stellar high-resolution
imaging in the near infrared wavelength range. Our PSSAO features
compact physical size, low cost and high performance. The AO
software is based on LabVIEW programing and the mechanical and
optical components are based on off-the-shelf commercial components,
which make a high quality, duplicable and rapid developed AO system
possible. In addition, our AO software is flexible, and can be used
with different telescopes with or without central obstruction. We
discuss our portable AO design philosophy, and present our recent
on-site observation results. According to our knowledge, this is the
first portable adaptive optics in the world that is able to work for
solar and stellar high-resolution imaging with good performances.
Title: A high-contrast coronagraph for earth-like exoplanet direct
imaging: design and test
Authors: Liu, C. C.; Ren, D. Q.; Dou, J. P.; Zhu, Y. T.; Zhang, X.;
Zhao, G.; Wu, Zh.; Chen, R.
Bibcode: 2014arXiv1406.2364L
Altcode:
The high-contrast coronagraph for direct imaging earth-like exoplanet at
the visible needs a contrast of 10^(-10) at a small angular separation
of 4 lambda/D or less. Here we report our recent laboratory experiment
that is close to the limits. The test of the high-contrast imaging
coronagraph is based on our step-transmission apodized filter. To
achieve the goal, we use a liquid crystal array (LCA) as a phase
corrector to create a dark hole based on our dedicated focal dark
algorithm. We have suppressed the diffracted and speckle noise near
the star point image to a level of 1.68 x 10^(-9) at 4 lambda/D,
which can be immediately used for the direct imaging of Jupiter like
exoplanets. This demonstrates that high-contrast coronagraph telescope
in space has the potentiality to detect and characterize earth-like
planets.
Title: GRB 130822A: weihai optical upper limit.
Authors: Xu, D.; Ren, D. -Y.; Cao, C.; Hu, S. -M.
Bibcode: 2013GCN.15114....1X
Altcode: 2013GCN..15114...1X
No abstract at ADS
Title: GRB 130821A: weihai optical upper limit.
Authors: Xu, D.; Ren, D. -Y.; Cao, C.; Hu, S. -M.
Bibcode: 2013GCN.15124....1X
Altcode: 2013GCN..15124...1X
No abstract at ADS
Title: GRB 130420B: weihai optical upper limit.
Authors: Xu, D.; Cao, C.; Hu, S.; Ren, D.
Bibcode: 2013GCN.14426....1X
Altcode: 2013GCN..14426...1X
No abstract at ADS
Title: A dark-hole correction test for the step-transmission filter
based coronagraphic system
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Li, Rong
Bibcode: 2012SPIE.8442E..0DD
Altcode:
We present the initial test of the dark-hole correction for the
high-contrast imaging coronagraph that is based on the step-transmission
filter. The dark hole is created by a 12x12 actuator deformable mirror
(DM) that has been put in the conjugate plane of the pupil image of
the coronagraph. In this test, we use the stochastic parallel gradient
descent (SPGD) optimization algorithm to directly control the DM to
provide an optimal phase to minimize the intensity in target regions,
where the dark hole is created and the contrast can be enhanced. For
demonstration purpose, the test is carried out in a single wavelength
and should be improved in next step for broad-band high-contrast
imaging. Finally, it is shown in the test that an extra contrast ~50
times improvement has reached in the dark hole in the coronagraphic
image plane. Such a technique could be used for a future space-based
high-contrast observation and is promising for the direct imaging of
an Earth-like exoplanet.
Title: Laboratory test of a polarimetry imaging subtraction system
for the high-contrast imaging
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Li, Rong
Bibcode: 2012SPIE.8446E..8DD
Altcode:
We propose a polarimetry imaging subtraction test system that can be
used for the direct imaging of the reflected light from exoplanets. Such
a system will be able to remove the speckle noise scattered by the
wave-front error and thus can enhance the high-contrast imaging. In this
system, we use a Wollaston Prism (WP) to divide the incoming light into
two simultaneous images with perpendicular linear polarizations. One
of the images is used as the reference image. Then both the phase
and geometric distortion corrections have been performed on the other
image. The corrected image is subtracted with the reference image to
remove the speckles. The whole procedure is based on an optimization
algorithm and the target function is to minimize the residual speckles
after subtraction. For demonstration purpose, here we only use a
circular pupil in the test without integrating of our apodized-pupil
coronagraph. It is shown that best result can be gained by inducing
both phase and distortion corrections. Finally, it has reached an extra
contrast gain of 50-times improvement in average, which is promising
to be used for the direct imaging of exoplanets.
Title: A demonstration test of the dual-beam polarimetry differential
imaging system for the high-contrast observation
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian; Wang, Xue; Zhang,
Xi; Li, Rong
Bibcode: 2012SPIE.8446E..1XD
Altcode:
We propose a dual-beam polarimetry differential imaging test system that
can be used for the direct imaging of the exoplanets. The system is
composed of a liquid crystal variable retarder (LCVR) in the pupil to
switch between two orthogonal polarized states, and a Wollaston prism
(WP) that will be inserted before the final focal focus of the system
to create two polarized images for the differential subtraction. Such a
system can work separately or be integrated in the coronagraph system
to enhance the high-contrast imaging. To demonstrate the feasibility
of the proposed system, here we show the initial test result both with
and without integrating our developed coronagraph. A unique feature
for this system is that each channel can subtract with itself by using
the retarder to rotate the planet's polarization orientation, which
has the best performance according to our lab test results. Finally,
it is shown that the polarimetry differential imaging system is a
promising technique and can be used for the direct imaging observation
of reflected lights from the exoplanets.
Title: Recent progress on the portable solar adaptive optics
Authors: Ren, Deqing; Zhang, Xi; Penn, Matt; Wang, Haimin; Dou,
Jiangpei; Zhu, Yongtian; Rong, Li; Wang, Xue
Bibcode: 2012SPIE.8447E..3KR
Altcode:
The portable solar adaptive optics is a compact adaptive optics system
that will be the first visitor solar instrument in the world. As so,
it will be able to work with any solar telescope with a aperture
size up to ~ 2.0 meters, which will cover the largest solar telescope
currently operational. The portable AO features small physical size,
high-flexibility and high-performance, and is a duplicable and
affordable system. It will provide wave-front correction down to
the 0.5-μm wavelength, and will be used for solar high-resolution
imaging in the near infrared and the visible. It will be the first AO
system that uses LabVIEW based high quality parallel and block-diagram
programming, which fully takes advantage of today's multi-core CPUs, and
makes a rapid development of an AO system possible. In this publication,
we report our recent progress on the portable adaptive optics, which
includes the laboratory test for performance characterization, and
initial on-site scientific observations.
Title: Speckle Noise Subtraction and Suppression with Adaptive Optics
Coronagraphic Imaging
Authors: Ren, Deqing; Dou, Jiangpei; Zhang, Xi; Zhu, Yongtian
Bibcode: 2012ApJ...753...99R
Altcode:
Future ground-based direct imaging of exoplanets depends critically on
high-contrast coronagraph and wave-front manipulation. A coronagraph
is designed to remove most of the unaberrated starlight. Because of
the wave-front error, which is inherit from the atmospheric turbulence
from ground observations, a coronagraph cannot deliver its theoretical
performance, and speckle noise will limit the high-contrast imaging
performance. Recently, extreme adaptive optics, which can deliver an
extremely high Strehl ratio, is being developed for such a challenging
mission. In this publication, we show that barely taking a long-exposure
image does not provide much gain for coronagraphic imaging with adaptive
optics. We further discuss a speckle subtraction and suppression
technique that fully takes advantage of the high contrast provided by
the coronagraph, as well as the wave front corrected by the adaptive
optics. This technique works well for coronagraphic imaging with
conventional adaptive optics with a moderate Strehl ratio, as well
as for extreme adaptive optics with a high Strehl ratio. We show
how to substrate and suppress speckle noise efficiently up to the
third order, which is critical for future ground-based high-contrast
imaging. Numerical simulations are conducted to fully demonstrate
this technique.
Title: Correction of Non-Common-Path Error for Extreme Adaptive Optics
Authors: Ren, Deqing; Dong, Bing; Zhu, Yongtian; Christian, Damian J.
Bibcode: 2012PASP..124..247R
Altcode:
The future direct imaging of exoplanets depends critically on
wave-front corrections. Extreme adaptive optics is being proposed to
meet such a critical requirement. One limitation to the performance of
adaptive optics is the differential wave-front aberration that is not
measured by a conventional wave-front sensor because of the so-called
non-common-path error. In this article, we propose a simple approach
that can be used to eliminate differential aberration with extreme
adaptive optics and is optimized for best image performance or directly
optimized for high-contrast coronagraphic imaging. The approach that
we propose can correct differential aberration in a single step, which
guarantees high accuracy and allows adaptive optics to correct the
differential aberration on a real-time scale. This approach is based
on an iterative optimization algorithm that commands the deformable
mirror directly and uses the focal-plane point-spread function as a
metric function to evaluate the correction performance.
Title: Isotopic Composition of Light Nuclei in Cosmic Rays: Results
from AMS-01
Authors: Aguilar, M.; Alcaraz, J.; Allaby, J.; Alpat, B.; Ambrosi, G.;
Anderhub, H.; Ao, L.; Arefiev, A.; Arruda, L.; Azzarello, P.; Basile,
M.; Barao, F.; Barreira, G.; Bartoloni, A.; Battiston, R.; Becker,
R.; Becker, U.; Bellagamba, L.; Berdugo, J.; Berges, P.; Bertucci, B.;
Biland, A.; Bindi, V.; Boella, G.; Boschini, M.; Bourquin, M.; Bruni,
G.; Buénerd, M.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Cannarsa,
P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cernuda, I.;
Chang, Y. H.; Chen, H. F.; Chen, H. S.; Chen, Z. G.; Chernoplekov,
N. A.; Chiueh, T. H.; Choi, Y. Y.; Cindolo, F.; Commichau, V.; Contin,
A.; Cortina-Gil, E.; Crespo, D.; Cristinziani, M.; Dai, T. S.; dela
Guia, C.; Delgado, C.; Di Falco, S.; Djambazov, L.; D'Antone, I.;
Dong, Z. R.; Duranti, M.; Engelberg, J.; Eppling, F. J.; Eronen, T.;
Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P. H.; Flügge,
G.; Fouque, N.; Galaktionov, Y.; Gervasi, M.; Giovacchini, F.;
Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.; Haino, S.; Hangarter,
K.; Hasan, A.; Hermel, V.; Hofer, H.; Hungerford, W.; Ionica, M.;
Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kim, D. H.;
Kim, G. N.; Kim, K. S.; Kirn, T.; Klimentov, A.; Kossakowski, R.;
Kounine, A.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen,
T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lechanoine-Leluc, C.;
Lee, M. W.; Lee, S. C.; Levi, G.; Lin, C. H.; Liu, H. T.; Lu, G.;
Lu, Y. S.; Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña, C.;
Margotti, A.; Mayet, F.; McNeil, R. R.; Menichelli, M.; Mihul, A.;
Mujunen, A.; Natale, S.; Oliva, A.; Palmonari, F.; Paniccia, M.; Park,
H. B.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Pereira, R.; Perrin, E.;
Pevsner, A.; Pilo, F.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl,
M.; Produit, N.; Quadrani, L.; Rancoita, P. G.; Rapin, D.; Ren, D.;
Ren, Z.; Ribordy, M.; Riihonen, E.; Ritakari, J.; Ro, S.; Roeser,
U.; Sagdeev, R.; Santos, D.; Sartorelli, G.; Saouter, P.; Sbarra,
C.; Schael, S.; Schultz von Dratzig, A.; Schwering, G.; Seo, E. S.;
Shin, J. W.; Shoumilov, E.; Shoutko, V.; Siedenburg, T.; Siedling,
R.; Son, D.; Song, T.; Spada, F. R.; Spinella, F.; Steuer, M.; Sun,
G. S.; Suter, H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.;
Tomassetti, N.; Tornikoski, M.; Torsti, J.; Trümper, J.; Ulbricht,
J.; Urpo, S.; Valtonen, E.; Vandenhirtz, J.; Velikhov, E.; Verlaat,
B.; Vetlitsky, I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.;
Von Gunten, H.; Waldmeier Wicki, S.; Wallraff, W.; Wang, J. Z.; Wiik,
K.; Williams, C.; Wu, S. X.; Xia, P. C.; Xu, S.; Xu, Z. Z.; Yan, J. L.;
Yan, L. G.; Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Zhang, H. Y.;
Zhang, Z. P.; Zhao, D. X.; Zhou, F.; Zhou, Y.; Zhu, G. Y.; Zhu, W. Z.;
Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.
Bibcode: 2011ApJ...736..105A
Altcode: 2011arXiv1106.2269T
The variety of isotopes in cosmic rays allows us to
study different aspects of the processes that cosmic rays
undergo between the time they are produced and the time of
their arrival in the heliosphere. In this paper, we present
measurements of the isotopic ratios 2H/4He,
3He/4He, 6Li/7Li,
7Be/(9Be+10Be), and
10B/11B in the range 0.2-1.4 GeV of kinetic
energy per nucleon. The measurements are based on the data collected
by the Alpha Magnetic Spectrometer, AMS-01, during the STS-91 flight
in 1998 June.
Title: A Coronagraph Using a Liquid Crystal Array and a Deformable
Mirror for Active Apodizing and Phase Corrections
Authors: Ren, Deqing; Zhu, Yongtian
Bibcode: 2011PASP..123..341R
Altcode:
Almost all high-contrast imaging coronagraphs proposed until now
are based on passive coronagraph optical components. That is, the
coronagraph cannot be actively controlled to be optimized for best
performance. Pupil apodizing, which modifies the light transmission
on the pupil, is one of the promising techniques for high-contrast
imaging. Here, we propose, for the first time, a high-contrast imaging
coronagraph that integrates a liquid crystal array for active pupil
apodizing and a deformable mirror for active phase correction. In
such a way, source errors such as the initial transmission error and
wavefront error can be actively and efficiently compensated based on
an optimized algorithm, which is optimized for maximum contrast in
the discovery area. In addition, the use of a liquid crystal array
makes this system more flexible and able to create any apodizing
pupil, including square or circle aperture with or without central
obstruction. In this article, we discuss the working principle and
estimated performance of the coronagraph. We also demonstrate that the
chromatic aberration induced by a liquid crystal array is sufficiently
small, which makes it suitable to be used for ground-based near-infrared
coronagraphic Extreme-AO systems.
Title: Relative Composition and Energy Spectra of Light Nuclei in
Cosmic Rays: Results from AMS-01
Authors: Aguilar, M.; Alcaraz, J.; Allaby, J.; Alpat, B.; Ambrosi,
G.; Anderhub, H.; Ao, L.; Arefiev, A.; Arruda, L.; Azzarello, P.;
Basile, M.; Barao, F.; Barreira, G.; Bartoloni, A.; Battiston, R.;
Becker, R.; Becker, U.; Bellagamba, L.; Béné, P.; Berdugo, J.;
Berges, P.; Bertucci, B.; Biland, A.; Bindi, V.; Boella, G.; Boschini,
M.; Bourquin, M.; Bruni, G.; Buénerd, M.; Burger, J. D.; Burger,
W. J.; Cai, X. D.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus,
J.; Castellini, G.; Cernuda, I.; Chang, Y. H.; Chen, H. F.; Chen,
H. S.; Chen, Z. G.; Chernoplekov, N. A.; Chiueh, T. H.; Choi, Y. Y.;
Cindolo, F.; Commichau, V.; Contin, A.; Cortina-Gil, E.; Crespo, D.;
Cristinziani, M.; Dai, T. S.; dela Guia, C.; Delgado, C.; Di Falco,
S.; Djambazov, L.; D'Antone, I.; Dong, Z. R.; Duranti, M.; Engelberg,
J.; Eppling, F. J.; Eronen, T.; Extermann, P.; Favier, J.; Fiandrini,
E.; Fisher, P. H.; Flügge, G.; Fouque, N.; Galaktionov, Y.; Gervasi,
M.; Giovacchini, F.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.;
Haino, S.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Hungerford,
W.; Ionica, M.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney,
G.; Kim, D. H.; Kim, G. N.; Kim, K. S.; Kirn, T.; Klimentov, A.;
Kossakowski, R.; Kounine, A.; Koutsenko, V.; Kraeber, M.; Laborie, G.;
Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lechanoine-Leluc,
C.; Lee, M. W.; Lee, S. C.; Levi, G.; Lin, C. H.; Liu, H. T.; Lu,
G.; Lu, Y. S.; Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña,
C.; Margotti, A.; Mayet, F.; McNeil, R. R.; Menichelli, M.; Mihul,
A.; Mujunen, A.; Oliva, A.; Palmonari, F.; Park, H. B.; Park, W. H.;
Pauluzzi, M.; Pauss, F.; Pereira, R.; Perrin, E.; Pevsner, A.; Pilo,
F.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl, M.; Produit, N.;
Quadrani, L.; Rancoita, P. G.; Rapin, D.; Ren, D.; Ren, Z.; Ribordy,
M.; Richeux, J. P.; Riihonen, E.; Ritakari, J.; Ro, S.; Roeser, U.;
Sagdeev, R.; Santos, D.; Sartorelli, G.; Sbarra, C.; Schael, S.;
Schultz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shin, J. W.;
Shoumilov, E.; Shoutko, V.; Siedenburg, T.; Siedling, R.; Son, D.;
Song, T.; Spada, F. R.; Spinella, F.; Steuer, M.; Sun, G. S.; Suter,
H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.;
Tornikoski, M.; Torsti, J.; Trümper, J.; Ulbricht, J.; Urpo, S.;
Valtonen, E.; Vandenhirtz, J.; Velikhov, E.; Verlaat, B.; Vetlitsky,
I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.; Von Gunten, H.;
Waldmeier Wicki, S.; Wallraff, W.; Wang, J. Z.; Wiik, K.; Williams,
C.; Wu, S. X.; Xia, P. C.; Xu, S.; Xu, Z. Z.; Yan, J. L.; Yan, L. G.;
Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Zhang, H. Y.; Zhang,
Z. P.; Zhao, D. X.; Zhou, F.; Zhou, Y.; Zhu, G. Y.; Zhu, W. Z.;
Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.
Bibcode: 2010ApJ...724..329A
Altcode:
Measurement of the chemical and isotopic composition of cosmic rays
is essential for the precise understanding of their propagation in
the galaxy. While the model parameters are mainly determined using
the B/C ratio, the study of extended sets of ratios can provide
stronger constraints on the propagation models. In this paper, the
relative abundances of light-nuclei lithium, beryllium, boron, and
carbon are presented. The secondary-to-primary ratios Li/C, Be/C,
and B/C have been measured in the kinetic energy range 0.35-45 GeV
nucleon-1. The isotopic ratio 7Li/6Li
is also determined in the magnetic rigidity interval 2.5-6.3
GV. The secondary-to-secondary ratios Li/Be, Li/B, and Be/B are also
reported. These measurements are based on the data collected by the
Alpha Magnetic Spectrometer AMS-01 during the STS-91 space shuttle
flight in 1998 June. Our experimental results are in substantial
agreement with other measurements, where they exist. We describe our
light-nuclei data with a diffusive-reacceleration model. A 10%-15%
overproduction of Be is found in the model predictions and can be
attributed to uncertainties in the production cross-section data.
Title: A portable solar adaptive optics system: software and
laboratory developments
Authors: Ren, Deqing; Penn, Matt; Plymate, Claude; Wang, Haimin;
Zhang, Xi; Dong, Bing; Brown, Nathan; Denio, Andrew
Bibcode: 2010SPIE.7736E..3PR
Altcode: 2010SPIE.7736E.124R
We present our recent process on a portable solar adaptive Optics
system, which is aimed for diffraction-limited imaging in the 1.0 ~
5.0-μm infrared wavelength range with any solar telescope with an
aperture size up to 1.6 meters. The realtime wave-front sensing, image
processing and computation are based on a commercial multi-core personal
computer. The software is developed in LabVIEW. Combining the power of
multi-core imaging processing and LabVIEW parallel programming, we show
that our solar adaptive optics can achieve excellent performance that
is competitive with other systems. In addition, the LabVIEW's block
diagram based programming is especially suitable for rapid development
of a prototype system, which makes a low-cost and high-performance
system possible. Our adaptive optics system is flexible; it can
work with any telescope with or without central obstruction with
any aperture size in the range of 0.6~1.6 meters. In addition, the
whole system is compact and can be brought to a solar observatory to
perform associated scientific observations. According to our knowledge,
this is the first adaptive optics that adopts the LabVIEW high-level
programming language with a multi-core commercial personal computer,
and includes the unique features discussed above.
Title: Testing of a transmission-filter coronagraph for ground-based
imaging of exoplanets
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian; Zhang, Xi;
Wang, Xue
Bibcode: 2010SPIE.7735E..8ED
Altcode: 2010SPIE.7735E.273D
We present the latest laboratory test of a new coronagraph using one
step-transmission filter at the visible wavelength. The primary goal of
this work is to test the feasibility and stability of the coronagraph,
which is designed for the ground-based telescope especially with a
central obstruction and spider structures. The transmission filter
is circular symmetrically coated with inconel film on one surface
and manufactured with a precisely position-controlled physical mask
during the coating procedure. At first, the transmission tolerance of
the filter is controlled within 5% for each circular step. The target
contrast of the coronagraph is set to be 10-5~10-7
at an inner working angle around 5λ/D. Based on the high-contrast
imaging test-bed in the laboratory, the point spread function image
of the coronagraph is obtained and it has delivered a contrast better
than 10-6 at 5λ/D. As a follow-up effort, the transmission
error should be controlled in 2% and the transmission for such filter
will be optimized in the near infrared wavelength, which should deliver
better performances. Finally, it is shown that the transmission-filter
coronagraph is a promising technique to be used for the direct imaging
of exoplanets from the ground.
Title: A Transmission-Filter Coronagraph: Design and Test
Authors: Ren, Deqing; Dou, Jiangpei; Zhu, Yongtian
Bibcode: 2010PASP..122..590R
Altcode: 2015arXiv151003796R
We propose a transmission-filter coronagraph for direct imaging of
Jupiter-like exoplanets with ground-based telescopes. The coronagraph
is based on a transmission filter that consists of finite number of
transmission steps. A discrete optimization algorithm is proposed for
the design of the transmission filter that is optimized for ground-based
telescopes with central obstructions and spider structures. We discussed
the algorithm that is applied for our coronagraph design. To demonstrate
the performance of the coronagraph, a filter was manufactured and
laboratory tests were conducted. The test results show that the
coronagraph can achieve a high contrast of 10-6.5 at an
inner working angle of 5λ/D, which indicates that our coronagraph can
be immediately used for the direct imaging of Jupiter-like exoplanets
with ground-based telescopes.
Title: A portable solar adaptive optics system
Authors: Ren, Deqing; Penn, Matt; Wang, Haimin; Chapman, Gary;
Plymate, Claude
Bibcode: 2009SPIE.7438E..0PR
Altcode:
We are developing a portable adaptive optics system for solar
telescopes. The adaptive optics has a small physical size and is
optimized for diffraction-limited imaging in the 1.0 ~ 5.0-μm infrared
wavelength range for 1.5-m class solar telescopes. By replacing a
few optical components, it can be used with a solar telescope of any
aperture size that is currently available. The software is developed by
LabVIEW. LabVIEW's block diagram based programming makes it suitable for
rapid development of a prototype system. The portable adaptive optics
will be used with a 1.5-meter solar telescope for high-resolution
magnetic field investigation in the infrared. We discuss the design
philosophy for such a portable, low-cost, and high-performance
system. Estimated performances are also presented.
Title: Focal plane wave-front sensing algorithm for high-contrast
imaging
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian; Zhang, Xi
Bibcode: 2009ScChG..52.1284D
Altcode: 2015arXiv151003791D
High-contrast imaging provided by a coronagraph is critical for the
direction imaging of the Earth-like planet orbiting its bright parent
star. A major limitation for such direct imaging is the speckle noise
that is induced from the wave-front error of an optical system. We
derive an algorithm for the wave-front measurement directly from 3
focal plane images. The 3 images are achieved through a deformable
mirror to provide specific phases for the optics system. We introduce
an extra amplitude modulation on one deformable mirror configuration
to create an uncorrelated wave-front, which is a critical procedure
for wave-front sensing. The simulation shows that the reconstructed
wave-front is consistent with the original wave-front theoretically,
which indicates that such an algorithm is a promising technique for
the wave-front measurement for the high-contrast imaging.
Title: An IFU for diffraction-limited 3D spectroscopic imaging:
laboratory and on-site tests
Authors: Ren, Deqing; Keller, Christoph; Plymate, Claude
Bibcode: 2009SPIE.7438E..18R
Altcode: 2009SPIE.7438E..35R
We have developed a state-of-the-art image slicer Integral Field Unit
(IFU) for the McMath-Pierce Solar Telescope (McMP) located at Kitt Peak
National Solar Observatory. The IFU will be used for high-resolution
3-dimensional spectroscopy and polarimetry over a small field of
view that is well corrected by adaptive optics. It consists of 19
effective slices that correspond to a field of view of 6.27"x 7". The
IFU delivers a 152" long slit to an existing spectrograph producing
diffraction-limited 3-dimensional spectroscopy. The 3-D instrument is
being used for highspatial and high-temporal resolution imaging of the
Sun, which is crucial for the magnetic field and spectroscopic studies
of 2-dimensional solar fine structures. We discuss the instrument
construction, laboratory test and on-site trial observations with
the McMP.
Title: Wave-front sensing and correction for 4-meter LAMOST
Authors: Zhang, Xi; Ren, Deqing; Zhu, Yongtian; Dou, Jiangpei
Bibcode: 2009SPIE.7439E..0VZ
Altcode: 2009SPIE.7439E..20Z
LAMOST is a 4m spectroscopic telescope recently operational at Xinglong,
China. Several active optics are being used to remove optical aberration
of the telescope, but large residual aberration exists since the
active optics actuators on the telescope's segmented mirrors cannot
provide enough precision. We proposed a wave-front sensing system and
the corresponding algorithm to measure this low frequency residual
aberration. We developed a compact Shack-Hartmann wave-front sensor
that can use point source as well as extended structure images for
wave-front sensing and can achieve good measurement accuracy. The
wave-front sensing algorithm is realized by LabVIEW that is based
on block-diagram programming and is suitable for rapid prototype
development. Combined with deformable mirrors, the system will be able
to provide a fine wave-front correction and therefore eventually remove
the residual aberration for LAMOST. The wave-front sensor and the DMs
will also be used for our high-contrast imaging coronagraph to remove
speckle noise for the direct imaging of exoplanets.
Title: Laboratory experiment of a high-contrast imaging coronagraph
with new step-transmission filters
Authors: Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian; Zhang, Xi
Bibcode: 2009SPIE.7440E..19D
Altcode: 2009SPIE.7440E..37D
We present the latest results of our laboratory experiment of the
coronagraph with step-transmission filters. The primary goal of
this work is to test the stability of the coronagraph and identify
the main factors that limit its performance. At present, a series
of step-transmission filters has been designed. These filters were
manufactured with Cr film on a glass substrate with a high surface
quality. During the process of the experiment of each filter, we
have identified several contrast limiting factors, which includes
the non-symmetry of the coating film, transmission error, scattered
light and the optical aberration caused by the thickness difference
of coating film. To eliminate these factors, we developed a procedure
for the correct test of the coronagraph and finally it delivered a
contrast in the order of 10-6~10-7 at an angular
distance of 4λD, which is well consistent with theoretical design. As a
follow-up effort, a deformable mirror has been manufactured to correct
the wave-front error of the optical system, which should deliver
better performance with an extra contrast improvement in the order of
10-2~10-3. It is shown that the step-transmission
filter based coronagraph is promising for the high-contrast imaging
of earth-like planets.
Title: The eruption of a small filament in the quiet Sun
Authors: Ren, D. B.; Jiang, Y. C.; Yang, J. Y.; Zheng, R. S.; Bi,
Y.; Wang, M.
Bibcode: 2008Ap&SS.318..141R
Altcode: 2008Ap&SS.tmp..216R
We analyzed multi-wavelength observations of the eruption of a
small-scale filament on the quiet Sun. The filament first became
thicker, then broke into two, and eventually underwent a partial
eruption with possible rotating motion. The eruption was followed by a
small flare with three bright kernels on either side of the eruptive
section in H α and a small coronal dimming near one end of this
section in EUV and soft X-ray. On the photosphere, MDI magnetograms
show the flux emergence or motions and cancellation between opposite
polarities before and during the filament eruption. We find that this
small-scale filament shows the similar characteristics as the previous
findings in the large-scale filament eruptions on the multi-wavelength,
indicating the common nature.
Title: Study of the solar anisotropy of cosmic ray primaries of
about 200 GeV energy with the L3+C muon detector
Authors: L3 Collaboration; Achard, P.; Adriani, O.; Aguilar-Benitez,
M.; van den Akker, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio,
A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev,
A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay,
L.; Bähr, J.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.;
Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston,
R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.;
Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.;
Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.;
Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.;
Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu,
F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo,
G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo,
N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin,
M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.;
Chiarusi, T.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.;
Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.;
Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré,
A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.;
DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding,
L. K.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau,
D.; Duda, M.; Duran, I.; Echenard, B.; Eline, A.; El Mamouni, H.;
Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.;
Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson,
T.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, W.; Forconi,
G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.;
Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.;
Grabosch, H. J.; Grenier, G.; Grimm, O.; Groenstege, H.; Gruenewald,
M. W.; Guo, Y. N.; Gupta, S.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.;
Haas, D.; Haller, Ch.; Hatzifotiadou, D.; Hayashi, Y.; He, Z. X.;
Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hoferjun, H.;
Hohlmann, M.; Holzner, G.; Hou, S. R.; Huo, A. X.; Ito, N.; Jin, B. N.;
Jindal, P.; Jing, C. L.; Jones, L. W.; de Jong, P.; Josa-Mutuberría,
I.; Kantserov, V.; Kaur, M.; Kawakami, S.; Kienzle-Focacci, M. N.;
Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.;
Kok, E.; Korn, A.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kuang,
H. H.; Kraemer, R. W.; Krüger, A.; Kuijpers, J.; Kunin, A.; Ladron
de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.;
Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.;
Lei, Y.; Leich, H.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li,
C.; Li, L.; Li, Z. C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde,
F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci,
C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Ma, X. H.; Ma, Y. Q.;
Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano,
F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Meng, X. W.; Merola, L.;
Meschini, M.; Metzger, W. J.; Mihul, A.; van Mil, A.; Milcent, H.;
Mirabelli, G.; Mohanty, G. B.; Monteleoni, B.; Muanza, G. S.; Muijs,
A. J. M.; Musy, M.; Nagy, S.; Nahnhauer, R.; Naumov, V. A.; Natale,
S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak,
T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares,
C.; Paolucci, P.; Paramatti, R.; Parriaud, J. -F.; Passaleva, G.;
Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace,
M.; Pensotti, S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.;
Pierella, F.; Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.;
Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.;
Qing, C. R.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.;
Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Ravindran,
K. C.; Razis, P.; Rembeczki, S.; Ren, D.; Rescigno, M.; Reucroft,
S.; Rewiersma, P.; Riemann, S.; Riles, K.; Roe, B. P.; Rojkov, A.;
Romero, L.; Rosca, A.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.;
Ruggiero, G.; Rykaczewski, H.; Saidi, R.; Sakharov, A.; Saremi, S.;
Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.;
Schmitt, V.; Schoeneich, B.; Schopper, H.; Schotanus, D. J.; Sciacca,
C.; Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko,
V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.;
Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar,
K.; Sulanke, H.; Sultanov, G.; Sun, L. Z.; Suter, H.; Swain, J. D.;
Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.;
Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.; Ting,
S. M.; Tonwar, S. C.; Tóth, J.; Trowitzsch, G.; Tully, C.; Tung,
K. L.; Ulbricht, J.; Unger, M.; Valente, E.; Verkooijen, H.; Van de
Walle, R. T.; Vasquez, R.; Vesztergombi, G.; Vetlitsky, I.; Viertel,
G.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt,
H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, R. G.; Wang, Q.;
Wang, X. L.; Wang, X. W.; Wang, Z. M.; Weber, M.; van Wijk, R.; Wijnen,
T. A. M.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Y. P.; Xu, J. S.; Xu,
Z. Z.; Yamamoto, J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.;
Yang, X. F.; Yao, Z. G.; Yeh, S. C.; Yu, Z. Q.; Zalite, An.; Zalite,
Yu.; Zhang, C.; Zhang, F.; Zhang, J.; Zhang, S.; Zhang, Z. P.; Zhao,
J.; Zhou, S. J.; Zhu, G. Y.; Zhu, R. Y.; Zhu, Q. Q.; Zhuang, H. L.;
Zichichi, A.; Zimmermann, B.; Zöller, M.; Zwart, A. N. M.
Bibcode: 2008A&A...488.1093L
Altcode:
Context: Primary cosmic rays experience multiple deflections in
the non-uniform galactic and heliospheric magnetic fields which may
generate anisotropies.
Aims: A study of anisotropies in the
energy range between 100 and 500 GeV is performed. This energy range
is not yet well explored.
Methods: The L3 detector at the CERN
electron-positron collider, LEP, is used for a study of the angular
distribution of atmospheric muons with energies above 20 GeV. This
distribution is used to investigate the isotropy of the time-dependent
intensity of the primary cosmic-ray flux with a Fourier analysis.
Results: A small deviation from isotropy at energies around 200
GeV is observed for the second harmonics at the solar frequency. No
sidereal anisotropy is found at a level above 10-4. The
measurements were performed in the years 1999 and 2000.
Title: Observations of Comets
Authors: Sanner, J.; Hellmann, D.; Idel, B.; Niedermayer, C.;
Kupper, R.; Martin, P. M.; Rumpel, N.; Kubitscheck, L.; Stamm,
L.; Ivanov, V.; Kryachko, T.; Korotkiy, S.; Casali, M.; Marinello,
W.; Micheli, M.; Pizzetti, G.; Soffiantini, A.; Buzzi, L.; Naves,
R.; Campas, M.; Hasubick, W.; Reina, E.; Ligustri, R.; Kadota, K.;
Herald, D.; McAndrew, S. G.; Sanchez, A.; Rodriguez, D.; Christie,
G. W.; Natusch, T.; Donato, L.; Gonano, M.; Gonano, V.; Guido, E.;
Santini, V.; Sostero, G.; Gilmore, A. C.; Kilmartin, P. M.; Lai, L.;
Baransky, A.; Aleksakhina, E.; Csak, B.; Santa, G.; Haja, O.; Kozak,
M.; Young, J.; Hill, R. E.; Beshore, E. C.; Boattini, A.; Gibbs,
A. R.; Grauer, A. D.; Kowalski, R. A.; Larson, S. M.; Bezpalko, M.;
Torres, D.; Kracke, R.; Spitz, G.; Kistler, J.; Stuart, J.; Scruggs,
S.; Moritz, N.; Elliott, R.; Salvo, R.; Durig, D. T.; Lin, S. M.;
Whang, U.; Ren, D.; Kabir, N. K.; Phillips, R. M.; Owuor, B. R.;
Enoch, R. W.; Caruthers, T. A.; Bishnoi, M.; Solano, J. P.; Payne,
D. R.; Paz, J. M.; Ikari, Y.; Castellano, J.; Ferrando, R.; Vidal,
J. R.; Baldris, F.; Cortes, E.; Kocher, P.; Rinner, C.; Kugel, F.;
Franco, L.; Vollmann, W.; Bacci, P.; Villegas, J. M.; Aymami, J. M.;
Piludu, P.; Biasci, F.; Garrigos S., A.; Nevski, V.; Camarasa,
J.; Bel, J.; Overhaus, C.; Borghini, W.; Sommacal, D.; Ohshima,
Y.; Sugiyama, Y.; McNaught, R. H.; Garradd, G. J.; McCormick, J.;
Sherrod, P. C.; Sanchez, J. L.; Buso, V. A.; Mazalan, G. D.; Diez,
E. J.; Tifner, F.; Hernandez, J. F.; Garcia, F.; Moreno Q., J. A.;
Ruiz M., J. M.; Rodriguez R., F. A.; Piret, C.; Muler, G.; Henriquez,
J. A.; Canales, O.; Benavides, R.; Temprano, J.; Navarro P., J. P.;
Lacruz, J.; Birtwhistle, P.; Climent, T.; Marsden, B. G.
Bibcode: 2008MPEC....N...31S
Altcode:
No abstract at ADS
Title: Laboratory experiment of a coronagraph based on
step-transmission filters
Authors: Dou, Jiangpei; Zhu, Yongtian; Ren, Deqing; Zhang, Xi
Bibcode: 2008SPIE.7010E..4JD
Altcode: 2008SPIE.7010E.130D
This paper presents the first results of a step-transmission-filter
based coronagraph in the visible wavelengths. The primary goal of
this work is to demonstrate the feasibility of the coronagraph that
employs step-transmission filters, with a required contrast in the
order of better than 10-5 at an angular distance larger
than 4λ/D. Two 13-step-transmission filters were manufactured with 5%
transmission accuracy. The precision of the transmitted wave distortion
and the coating surface quality were not strictly controlled at this
time. Although in perfect case the coronagraph can achieve theoretical
contrast of 10-10, it only delivers 10-5 contrast
because of the transmission error, poor surface quality and wave-front
aberration stated above, which is in our estimation. Based on current
techniques, step-transmission filters with better coating surface
quality and high-precision transmission can be made. As a follow-up
effort, high-quality step-transmission filters are being manufactured,
which should deliver better performance. The step-transmission-filter
based coronagraph has the potential applications for future
high-contrast direct imaging of earth-like planets.
Title: Minor Planet Observations [850 Cordell-Lorenz Observatory,
Sewanee]
Authors: Durig, D. T.; Lin, S. M.; Whang, U.; Parrish, T. L.; Carter,
A. L.; Mitchell, W. M.; Kong, N. E.; Ren, D.; Kabir, N. K.; Thompson,
A. W.; Hubbard, M. A.; Searvance, S. M.; Weber, L. M.; Phillips,
R. M.; Owuor, B. R.; Enoch, R. W.; Caruthers, T. A.; Bishnoi, M.;
Solano, J. P.; Payne, D. R.; Paz, J. M.; Veselovskyi, S.
Bibcode: 2008MPC..63370...1D
Altcode:
No abstract at ADS
Title: Comet Observations [850 Cordell-Lorenz Observatory, Sewanee]
Authors: Durig, D. T.; Lin, S. M.; Whang, U.; Parrish, T. L.; Carter,
A. L.; Mitchell, W. M.; Kong, N. E.; Ren, D.; Kabir, N. K.; Thompson,
A. W.; Hubbard, M. A.; Searvance, S. M.; Weber, L. M.; Phillips,
R. M.; Owuor, B. R.; Enoch, R. W.; Caruthers, T. A.; Bishnoi, M.;
Solano, J. P.; Payne, D. R.; Paz, J. M.; Veselovskyi, S.
Bibcode: 2008MPC..63321..20D
Altcode:
No abstract at ADS
Title: A Coronagraph Based on Stepped-Transmission Filters
Authors: Ren, Deqing; Zhu, Yongtian
Bibcode: 2007PASP..119.1063R
Altcode:
We propose a coronagraph for direct imaging of Earth-like planets
orbiting nearby bright stars. The coronagraph is based on an apodization
pupil composed of two stepped-transmission filters. We show that the
coronagraph can achieve 10-10 high-contrast imaging at an
angular distance larger than (2-3)λ/D theoretically. The employment
of the stepped-transmission filters significantly simplifies the
manufacturing of the transmission pupil, making it possible to be used
for high-contrast imaging in practice.
Title: Cosmic-ray positron fraction measurement from 1 to 30 GeV
with AMS-01
Authors: AMS-01 Collaboration; Aguilar, M.; Alcaraz, J.; Allaby, J.;
Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello,
P.; Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier,
G.; Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba,
L.; Béné, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.;
Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.; Brocco, L.; Bruni,
G.; Buénerd, M.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Camps,
C.; Cannarsa, P.; Capell, M.; Cardano, F.; Casadei, D.; Casaus, J.;
Castellini, G.; Chang, Y. H.; Chen, H. F.; Chen, H. S.; Chen, Z. G.;
Chernoplekov, N. A.; Chiueh, T. H.; Cho, K.; Choi, M. J.; Choi, Y. Y.;
Cindolo, F.; Commichau, V.; Contin, A.; Cortina-Gil, E.; Cristinziani,
M.; Dai, T. S.; Delgado, C.; Difalco, S.; Djambazov, L.; D'Antone,
I.; Dong, Z. R.; Emonet, P.; Engelberg, J.; Eppling, F. J.; Eronen,
T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher,
P. H.; Flügge, G.; Fouque, N.; Galaktionov, Yu.; Gast, H.; Gervasi,
M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.; Hangarter, K.;
Hasan, A.; Hermel, V.; Hofer, H.; Hungerford, W.; Jongmanns, M.;
Karlamaa, K.; Karpinski, W.; Kenney, G.; Kim, D. H.; Kim, G. N.;
Kim, K. S.; Kim, M. Y.; Klimentov, A.; Kossakowski, R.; Kounine,
A.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna,
G.; Lanciotti, E.; Laurenti, G.; Lebedev, A.; Lechanoine-Leluc, C.;
Lee, M. W.; Lee, S. C.; Levi, G.; Liu, C. L.; Liu, H. T.; Lu, G.;
Lu, Y. S.; Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña, C.;
Margotti, A.; Mayet, F.; McNeil, R. R.; Meillon, B.; Menichelli, M.;
Mihul, A.; Mujunen, A.; Oliva, A.; Olzem, J.; Palmonari, F.; Park,
H. B.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci, A.;
Pevsner, A.; Pilo, F.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl,
M.; Produit, N.; Rancoita, P. G.; Rapin, D.; Raupach, F.; Ren, D.;
Ren, Z.; Ribordy, M.; Richeux, J. P.; Riihonen, E.; Ritakari, J.;
Ro, S.; Roeser, U.; Rossin, C.; Sagdeev, R.; Santos, D.; Sartorelli,
G.; Sbarra, C.; Schael, S.; Schultz von Dratzig, A.; Schwering, G.;
Seo, E. S.; Shin, J. W.; Shoumilov, E.; Shoutko, V.; Siedenburg,
T.; Siedling, R.; Son, D.; Song, T.; Spinella, F.; Steuer, M.; Sun,
G. S.; Suter, H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.;
Tornikoski, M.; Torsti, J.; Trümper, J.; Ulbricht, J.; Urpo, S.;
Valtonen, E.; Vandenhirtz, J.; Velikhov, E.; Verlaat, B.; Vetlitsky,
I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.; von Gunten,
H.; Waldmeier Wicki, S.; Wallraff, W.; Wang, B. C.; Wang, J. Z.;
Wiik, K.; Williams, C.; Wu, S. X.; Xia, P. C.; Xu, S.; Yan, J. L.;
Yan, L. G.; Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Xu, Z. Z.;
Zhang, H. Y.; Zhang, Z. P.; Zhao, D. X.; Zhou, Y.; Zhu, G. Y.; Zhu,
W. Z.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.
Bibcode: 2007PhLB..646..145A
Altcode: 2007astro.ph..3154A
A measurement of the cosmic ray positron fraction
e/(e+e) in the energy range of 1 30
GeV is presented. The measurement is based on data taken by the AMS-01
experiment during its 10 day Space Shuttle flight in June 1998. A proton
background suppression on the order of 106 is reached by
identifying converted bremsstrahlung photons emitted from positrons.
Title: The evolution of a complex solar radio burst corresponding
to special configuration of microwave sources
Authors: Xie, R. X.; Ren, D. B.; Liu, Y. Y.
Bibcode: 2007AdSpR..39.1474X
Altcode:
A complex radio burst associated with periodic (∼1 and 6 min)
pulsations and several kinds fine structures, e.g., normal- and
reverse-drifting type III bursts, zebra patterns, and slowly drifting
structure was observed with the radio spectrometers (1.0-2.0, 2.6-3.8,
5.2-7.6, and 0.65-1.5 GHz) at the National Astronomical Observatories
of China (NAOC) in Beijing and Yunnan on 19 October 2001. In combination
with the images of 17 and 34 GHz from NoRH and the magnetograms from MDI
we reveal the existence and evolution of preexisting and new emerging
sources, and find the horseshoe-shaped structure of microwave sources
intensity during the late phase of the burst. Through the detailed
comparison of the evolution of each source with the time profiles
of radio bursts corresponding to these sources we indicate that the
intimate correlation between the microwave sources evolution and the
generation of the radio burst associated fine structures. Some fine
structures can be considered as the MHD turbulence and plasma emission
mechanism, based on the anisotropic beam instability and hybrid waves
generations. From the characteristics of observations we may presume
that the coronal magnetic structures should contain an extended coronal
loop system and multiple discrete electrons acceleration/injection
sites. The mechanisms of this complex radio burst are deal with the
incoherent gyrosynchrotron emission from the trapped electrons and
the coherent plasma emission from the non trapped electrons.
Title: The solar flare of the 14th of July 2000 (L3+C detector
results)
Authors: Achard, P.; Adrian, O.; Aguilar-Benitez, M.; van den Akker,
M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.;
Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.;
Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Bähr, J.;
Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère,
R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.;
Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.;
Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.;
Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink,
G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov,
D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger,
J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino,
G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.;
Cerrada, M.; Chamizo, M.; Chiarusi, T.; Chang, Y. H.; Chemarin, M.;
Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari,
G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.;
Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; de
Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.;
Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani,
F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding, L. K.; Dionisi,
C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.;
Duran, I.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.;
Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.;
Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson,
T.; Fesefeldt, H; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher,
W.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.;
Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu,
S.; Gong, Z. F.; Grabosch, H. J.; Grenier, G.; Grimm, O.; Groenstege,
H.; Gruenewald, M. W.; Guida, M.; Guo, Y. N.; Gupta, S. K.; Gupta,
V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Haller, Ch.; Hatzifotiadou,
D.; Hayashi, Y.; He, Z. X.; Hebbeker, T.; Hervé, A.; Hirschfelder,
J.; Hofer, H.; Hofer, H.; Hohlmann, M.; Holzner, A.; Hou, S. R.; Huo,
A. X.; Ito, N.; Jin, B. N.; Jindal, P.; Jing, C. L.; Jones, L. W.;
de Jong, P.; Josa-Mutuberría, I.; Kantserov, V.; Kaur, M.; Kawakami,
S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.;
Klimentov, A.; König, A. C.; Kok, E.; Korn, A.; Kopal, M.; Koutsenko,
V.; Kräber, M.; Kuang, H. H.; Kraemer, R. W.; Krüger, A.; Kuijpers,
J.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau,
M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre,
P.; Le Goff, J. M.; Lei, Y.; Leich, H.; Leiste, R.; Levtchenko, M.;
Levtchenko, P.; Li, C.; Li, L.; Li, Z. C.; Likhoded, S.; Lin, C. H.;
Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo,
E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.;
Ma, X. H.; Ma, Y. Q.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.;
Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Meng, X. W.;
Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; van Mil, A.;
Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Monteleoni,
B.; Muanza, G. S.; Muijs, A. J. M.; Musy, M.; Nagy, S.; Nahnhauer,
R.; Naumov, V. A.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.;
Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.;
Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.;
Parriaud, J. -F.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi,
M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix,
D.; Petersen, B.; Piccolo, D.; Pierella, F.; Pieri, M.; Pioppi, M.;
Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.;
Pothier, J.; Prokofiev, D.; Qing, C. R.; Rahal-Callot, G.; Rahaman,
M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri,
R.; Raspereza, A.; Ravindran, K. C.; Razis, P.; Rembeczki, S.; Ren,
D.; Rescigno, M.; Reucroft, S.; Rewiersma, P.; Riemann, S.; Rojkov,
A.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees,
S.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov,
A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer,
C.; Schegelsky, V.; Schoeneich, B.; Schotanus, D. J.; Sciacca, C.;
Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko,
V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.;
Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar,
K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.;
Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.;
Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.; Ting,
S. M.; Tonwar, S. C.; Tóth, J.; Trowitzsch, G.; Tully, C.; Tung,
K. L.; Ulbricht, J.; Unger, M.; Valente, E.; Verkooijen, H.; Van de
Walle, R. T.; Vasquez, R.; Vesztergombi, G.; Vetlitsky, I.; Viertel,
G.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt,
H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, R. G.; Wang,
Q.; Wang, X. L.; Wang, X. W.; Wang, Z. M.; Weber, M.; van Wijk, R.;
Wijnen, T. A. M.; Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Y. P.; Xu,
Z. Z.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yang, X. F.;
Yao, Z. G.; Yeh, S. C.; Yu, Z. Q.; Zalite, An.; Zalite, Yu.; Zhang,
C.; Zhang, F.; Zhang, J.; Zhang, S.; Zhang, Z. P.; Zhao, J.; Zhou,
S. J.; Zhu, G. Y.; Zhu, R. Y; Zhu, Q. Q.; Zhuang, H. L.; Zichichi,
A.; Zimmermann, B.; Zöller, M.; Zwart, A. N. M.; L3 Collaboration
Bibcode: 2006A&A...456..351A
Altcode: 2006A&A...456..351L
Aims.Several experiments have reported observations on possible
correlations between the flux of high energy muons and intense solar
flares. If confirmed, these observations would have significant
implications for acceleration processes in the heliosphere able
to accelerate protons and other ions to energies of at least
tens of GeV. Methods: The solar flare of the 14 of July 2000
offered a unique opportunity for the L3+C experiment to search for
a correlated enhancement in the flux of muons using the L3 precision
muon spectrometer. Its capabilities for observing a directional excess
in the flux of muons above 15 GeV (corresponding to primary proton
energies above 40 GeV) are presented along with observations made on
the 14th of July 2000. Results: We report an excess which appeared at
a time coincident with the peak increase of solar protons observed
at lower energies. The probability that the excess is a background
fluctuation is estimated to be 1%. No similar excess of the muon flux
was observed up to 1.5 h after the solar flare time.
Title: Progress on the 1.6-meter New Solar Telescope at Big Bear
Solar Observatory
Authors: Denker, C.; Goode, P. R.; Ren, D.; Saadeghvaziri, M. A.;
Verdoni, A. P.; Wang, H.; Yang, G.; Abramenko, V.; Cao, W.; Coulter,
R.; Fear, R.; Nenow, J.; Shoumko, S.; Spirock, T. J.; Varsik, J. R.;
Chae, J.; Kuhn, J. R.; Moon, Y.; Park, Y. D.; Tritschler, A.
Bibcode: 2006SPIE.6267E..0AD
Altcode: 2006SPIE.6267E..10D
The New Solar Telescope (NST) project at Big Bear Solar Observatory
(BBSO) now has all major contracts for design and fabrication in place
and construction of components is well underway. NST is a collaboration
between BBSO, the Korean Astronomical Observatory (KAO) and Institute
for Astronomy (IfA) at the University of Hawaii. The project will
install a 1.6-meter, off-axis telescope at BBSO, replacing a number
of older solar telescopes. The NST will be located in a recently
refurbished dome on the BBSO causeway, which projects 300 meters into
the Big Bear Lake. Recent site surveys have confirmed that BBSO is
one of the premier solar observing sites in the world. NST will be
uniquely equipped to take advantage of the long periods of excellent
seeing common at the lake site. An up-to-date progress report will
be presented including an overview of the project and details on the
current state of the design. The report provides a detailed description
of the optical design, the thermal control of the new dome, the optical
support structure, the telescope control systems, active and adaptive
optics systems, and the post-focus instrumentation for high-resolution
spectro-polarimetry.
Title: Estimated performance of a symmetric nulling coronagraph for
exoplanet imaging
Authors: Ren, D.; Serabyn, E.
Bibcode: 2006SPIE.6265E..3XR
Altcode: 2006SPIE.6265E.119R
The direct detection of the earth-similar planets nearby bright stars
needs high-contrast imaging. We proposed a nulling coronagraph that can,
in principle, totally cancel the on-axis point-source starlight for
broadband high-contrast imaging. The nulling coronagraph also features
close angular distance imaging and high throughput. Equipped with a
telescope with only 1.5-m aperture size, it has the potentiality to be
able to resolving and directly detecting earth-similar planets at 0.1"
(1 λ/D) close-distance in the visible wavelength range. The requirement
for a small telescope is a significant advantage for future space
missions. We discuss the working principle, instrument realization,
error and sensitivity analysis, and the estimated performance of the
nulling coronagraph.
Title: Development of an IFU for diffraction-limited 3D
spectropolarimetry
Authors: Ren, Deqing; Keller, Christoph; Plymate, Claude
Bibcode: 2006SPIE.6269E..5ZR
Altcode: 2006SPIE.6269E.191R
Ground-based telescopes can achieve diffraction-limited images when
equipped with adaptive optics (AO). A major limitation of AO is the
small field of view, which is due to the limited isoplanatic patch
size. Nevertheless, conventional long-slit spectrographs cannot sample
the entire AO-corrected field of view in a single exposure. However,
equipped with a modern, large detector array, the Integral Field
Unit (IFU) technique will allow a 3-dimensional (3-D) data cube to
be recorded simultaneously over the entire AO corrected field of
view, with a conventional long-slit spectrographs. We are building a
state-of-the-art image slicer IFU for the National Solar Observatory's
(NSO) McMath-Pierce Solar Telescope (McMP). This will be the first time
that an advanced image slicer IFU is used for 3-D spectroscopy and
polarimetry at a solar telescope. The IFU consists of 25 slices that
will sample a 6.25" x 8" AO corrected field of view simultaneously,
and produces a 200" long slit for diffraction-limited 3-D spectroscopy
and polarimetry. This IFU 3-D technique will provide the most high
spatial, high temporal resolution with high throughput for solar
spectroscopy and polarimetry. This is critical for state-of-the-art
spectral diagnosis of solar velocity and magnetic fields. We discuss
the design, construction, and testing of this new IFU.
Title: A search for flaring very-high-energy cosmic γ-ray sources
with the L3+C muon spectrometer
Authors: L3 Collaboration; Adriani, O.; Aguilar-Benitez, M.; van
den Akker, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.;
Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev,
A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay,
L.; Bähr, J.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.;
Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.;
Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco,
R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.;
Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink,
G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov,
D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger,
J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino,
G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.;
Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen,
G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiarusi, T.; Chiefari, G.;
Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino,
N.; Costantini, S.; de La Cruz, B.; Cucciarelli, S.; de Asmundis,
R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters,
K.; Della Volpe, D.; Delmeire, E.; Denes, P.; Denotaristefani, F.;
de Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding, L. K.; Dionisi,
C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.;
Duran, I.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.;
Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.;
Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson,
T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher,
P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta,
C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.;
Gentile, S.; Giagu, S.; Gong, Z. F.; Grabosch, H. J.; Grenier, G.;
Grimm, O.; Groenstege, H.; Gruenewald, M. W.; Guida, M.; Guo, Y. N.;
Gupta, S. K.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Haller,
Ch.; Hatzifotiadou, D.; Hayashi, Y.; He, Z. X.; Hebbeker, T.; Hervé,
A.; Hirschfelder, J.; Hofer, H.; Hofer, H.; Hohlmann, M.; Holzner, G.;
Hou, S. R.; Huo, A. X.; Ito, N.; Jin, B. N.; Jindal, P.; Jing, C. L.;
Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kantserov, V.; Kaur,
M.; Kawakami, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.;
Kittel, W.; Klimentov, A.; König, A. C.; Kok, E.; Korn, A.; Kopal,
M.; Koutsenko, V.; Kräber, M.; Kuang, H. H.; Kraemer, R. W.; Krüger,
A.; Kuijpers, J.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.;
Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq,
P.; Le Coultre, P.; Le Goff, J. M.; Lei, Y.; Leich, H.; Leiste, R.;
Levtchenko, M.; Levtchenko, P.; Li, C.; Li, L.; Li, Z. C.; Likhoded,
S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.;
Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann,
W.; Ma, W. G.; Ma, X. H.; Ma, Y. Q.; Malgeri, L.; Malinin, A.; Maña,
C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.;
Mele, S.; Meng, X. W.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul,
A.; van Mil, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.;
Monteleoni, B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy,
M.; Nagy, S.; Nahnhauer, R.; Naumov, V. A.; Natale, S.; Napolitano,
M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.;
Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci,
P.; Paramatti, R.; Parriaud, J. -F.; Passaleva, G.; Patricelli, S.;
Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti,
S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.;
Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.;
Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Quartieri, J.;
Qing, C. R.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.;
Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Ravindran,
K. C.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Rewiersma, P.;
Riemann, S.; Riles, K.; Roe, B. P.; Rojkov, A.; Romero, L.; Rosca, A.;
Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.;
Ruggiero, G.; Rykaczewski, H.; Saidi, R.; Sakharov, A.; Saremi, S.;
Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.;
Schmitt, V.; Schoeneich, B.; Schopper, H.; Schotanus, D. J.; Sciacca,
C.; Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko,
V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.;
Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar,
K.; Sulanke, H.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.;
Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.;
Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel
C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Trowitzsch, G.; Tully,
C.; Tung, K. L.; Ulbricht, J.; Unger, M.; Valente, E.; Verkooijen,
H.; van de Walle, R. T.; Vasquez, R.; Veszpremi, V.; Vesztergombi,
G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent,
M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.;
Vorobyov, A. A.; Wadhwa, M.; Wang, R. G.; Wang, Q.; Wang, X. L.;
Wang, X. W.; Wang, Z. M.; Weber, M.; van Wijk, R.; Wijnen, T. A. M.;
Wilkens, H.; Wynhoff, S.; Xia, L.; Xu, Y. P.; Xu, J. S.; Xu, Z. Z.;
Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yang, X. F.; Yao,
Z. G.; Yeh, S. C.; Yu, Z. Q.; Zalite, An.; Zalite, Yu.; Zhang, C.;
Zhang, F.; Zhang, J.; Zhang, S.; Zhang, Z. P.; Zhao, J.; Zhou, S. J.;
Zhu, G. Y.; Zhu, R. Y.; Zhu, Q. Q.; Zhuang, H. L.; Zichichi, A.;
Zimmermann, B.; Zöller, M.; Zwart, A. N. M.
Bibcode: 2006APh....25..298A
Altcode: 2006APh....25..298L; 2006APh....25..298T
The L3+C muon detector at the CERN electron positron collider, LEP,
is used for the detection of very-high-energy cosmic γ-ray sources
through the observation of muons of energies above 20, 30, 50 and
100 GeV. Daily or monthly excesses in the rate of single-muon events
pointing to some particular direction in the sky are searched for. The
periods from mid July to November 1999, and April to November 2000 are
considered. Special attention is also given to a selection of known
γ-ray sources. No statistically significant excess is observed for
any direction or any particular source.
Title: Spectral Subtraction: A New Approach to Remove Low- and
High-Order Speckle Noise
Authors: Ren, Deqing; Wang, Haimin
Bibcode: 2006ApJ...640..530R
Altcode:
We present a novel ``spectral subtraction algorithm'' (SSA) technique
to remove speckle noise. It consists of a low-order and a high-order
SSA and is based on a three-dimensional image spectroscopy in which
the three-dimensional data cube is available and thus the speckle noise
introduced by the wave-front error can be efficiently subtracted. For
the low-order SSA, speckles up to the second or third order can be
totally subtracted, leaving the residual speckles dominated only by the
third or fourth order, respectively, and imaging contrast is increased
consequently; for the high-order SSA, speckles up to the fourth or fifth
order can be subtracted, leaving the residual speckles dominated only by
the fifth or sixth order, respectively, and the performance is further
improved. This is the first demonstration that such high-order speckles
could be subtracted. Since the SSAs are conducted over a wide spectral
band, a white-light image can be re-assembled from the three-dimensional
data cube. The white-light image would increase the single-to-noise
ratio and reduce the exposure time, which are crucial for the search
of faint companion objects. Combined with a coronagraph, the SSA can
provide an extra contrast gain for the coronagraph imaging, relax the
requirement for the wave-front quality (no adaptive optics correction is
required for a space-borne imaging system), and significantly increase
the performance of exoplanet imaging and biomarker spectroscopy.
Title: Symmetric nulling coronagraph based on a rotational shearing
interferometer
Authors: Ren, Deqing; Serabyn, Eugene
Bibcode: 2005ApOpt..44.7070R
Altcode:
We describe a fully symmetric nulling coronagraph for single-aperture
telescopes that is based on a rotational shearing interferometer
(RSI) and that is intended for the imaging of faint companions to
nearby bright stars. In the proposed layout, all asymmetries inherent
in previous single-aperture RSI-based nulling coronagraphs have been
eliminated, and the bright and dark outputs are both accessible. As
a result, deep, broadband, dual-polarization rejection of on-axis
starlight should be possible with this system.
Title: A study of cosmic ray secondaries induced by the Mir space
station using AMS-01
Authors: Aguilar, M.; Alcaraz, J.; Allaby, J.; Alpat, B.; Ambrosi,
G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello, P.; Babucci, E.;
Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier, G.;
Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba,
L.; Béné, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.;
Bizzaglia, S.; Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.;
Brocco, L.; Bruni, G.; Buénerd, M.; Burger, J. D.; Burger, W. J.;
Cai, X. D.; Camps, C.; Cannarsa, P.; Capell, M.; Carosi, G.; Casadei,
D.; Casaus, J.; Castellini, G.; Cecchi, C.; Chang, Y. H.; Chen, H. F.;
Chen, H. S.; Chen, Z. G.; Chernoplekov, N. A.; Chiueh, T. H.; Cho, K.;
Choi, M. J.; Choi, Y. Y.; Chuang, Y. L.; Cindolo, F.; Commichau, V.;
Contin, A.; Cortina-Gil, E.; Cristinziani, M.; da Cunha, J. P.; Dai,
T. S.; Delgado, C.; Demirköz, B.; Deus, J. D.; Dinu, N.; Djambazov,
L.; D'Antone, I.; Dong, Z. R.; Emonet, P.; Engelberg, J.; Eppling,
F. J.; Eronen, T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini,
E.; Fisher, P. H.; Fluegge, G.; Fouque, N.; Galaktionov, Yu.; Gervasi,
M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W. Q.; Hangarter, K.; Hasan,
A.; Henning, R.; Hermel, V.; Hofer, H.; Huang, M. A.; Hungerford,
W.; Ionica, M.; Ionica, R.; Jongmanns, M.; Karlamaa, K.; Karpinski,
W.; Kenney, G.; Kenny, J.; Kim, D. H.; Kim, G. N.; Kim, K. S.; Kim,
M. Y.; Klimentov, A.; Kossakowski, R.; Koutsenko, V.; Kraeber, M.;
Laborie, G.; Laitinen, T.; Lamanna, G.; Lanciotti, E.; Laurenti, G.;
Lebedev, A.; Lechanoine-Leluc, C.; Lee, M. W.; Lee, S. C.; Levi, G.;
Levtchenko, P.; Liu, C. L.; Liu, H. T.; Lopes, I.; Lu, G.; Lu, Y. S.;
Lübelsmeyer, K.; Luckey, D.; Lustermann, W.; Maña, C.; Margotti,
A.; Mayet, F.; McNeil, R. R.; Meillon, B.; Menichelli, M.; Mihul,
A.; Monreal, B.; Mourao, A.; Mujunen, A.; Palmonari, F.; Papi, A.;
Park, H. B.; Park, W. H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci,
A.; Pevsner, A.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Pohl, M.;
Postolache, V.; Produit, N.; Rancoita, P. G.; Rapin, D.; Raupach,
F.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J. P.; Riihonen, E.;
Ritakari, J.; Ro, S.; Roeser, U.; Rossin, C.; Sagdeev, R.; Santos,
D.; Sartorelli, G.; Sbarra, C.; Schael, S.; Schultz von Dratzig, A.;
Schwering, G.; Scolieri, G.; Seo, E. S.; Shin, J. W.; Shoumilov, E.;
Shoutko, V.; Siedling, R.; Son, D.; Song, T.; Steuer, M.; Sun, G. S.;
Suter, H.; Tang, X. W.; Ting, Samuel C. C.; Ting, S. M.; Tornikoski,
M.; Torsti, J.; Trümper, J.; Ulbricht, J.; Urpo, S.; Valtonen, E.;
Vandenhirtz, J.; Velcea, F.; Velikhov, E.; Verlaat, B.; Vetlitsky,
I.; Vezzu, F.; Vialle, J. P.; Viertel, G.; Vité, D.; von Gunten,
H.; Waldmeier Wicki, S.; Wallraff, W.; Wang, B. C.; Wang, J. Z.;
Wang, Y. H.; Wiik, K.; Williams, C.; Wu, S. X.; Xia, P. C.; Yan,
J. L.; Yan, L. G.; Yang, C. G.; Yang, J.; Yang, M.; Ye, S. W.; Yeh,
P.; Xu, Z. Z.; Zhang, H. Y.; Zhang, Z. P.; Zhao, D. X.; Zhu, G. Y.;
Zhu, W. Z.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zuccon, P.
Bibcode: 2005NIMPB.234..321A
Altcode: 2004hep.ex....6065T; 2004hep.ex....6065C
The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle
physics experiment that will study cosmic rays in the ∼100 MeV to
1 TeV range and will be installed on the International Space Station
(ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew
aboard the space shuttle Discovery from June 2 to June 12, 1998,
and collected 108 cosmic ray triggers. Part of the Mir
space station was within the AMS-01 field of view during the four day
Mir docking phase of this flight. We have reconstructed an image of
this part of the Mir space station using secondary π-
and μ- emissions from primary cosmic rays interacting
with Mir. This is the first time this reconstruction was performed in
AMS-01, and it is important for understanding potential backgrounds
during the 3 year AMS-02 mission.
Title: The New Solar Telescope at Big Bear Solar Observatory -
A Progress Report
Authors: Denker, C.; Cao, W.; Chae, J.; Coulter, R.; Kuhn, J. R.;
Marquette, W. H.; Moon, Y.; Park, Y.; Ren, D.; Tritschler, A.; Varsik,
J. R.; Wang, H.; Yang, G.; Shoumko, S.; Goode, P. R.
Bibcode: 2005AGUSMSP43A..07D
Altcode:
The New Solar Telescope (NST) is a new 1.6-meter, off-axis telescope
for the Big Bear Solar Observatory (BBSO) in California. The NST is
collaboration between BBSO, the Korean Astronomical Observatory (KAO)
and Institute for Astronomy (IfA) at the University of Hawaii. BBSO
is an ideal site for high-spatial resolution observations, since this
mountain-lake site provides consistent seeing conditions with extended
periods of excellent seeing from sunrise to sunset. These unique seeing
characteristics make BBSO ideally suited for combined high-resolution
campaigns and synoptic observations, which are essential for studies
of solar activity and space weather. In this progress report, we
present the latest information on the optical design, the optical
support structure, the telescope control system and the requisite
instrumentation for the telescope. Acknowledgements: This work has been
supported by NSF under grants ATM-0236945, ATM-0342560, MRI-0320540,
and Air Force DURIP F-49620-03-1-0271.
Title: Measurement of the shadowing of high-energy cosmic rays by
the Moon: A search for TeV-energy antiprotons
Authors: L3 Collaboration; Achard, P.; Adriani, O.; Aguilar-Benitez,
M.; van den Akker, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio,
A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev,
A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay,
L.; Bähr, J.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.;
Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.;
Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco,
R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.;
Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink,
G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov,
D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger,
J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Romeo, G. Cara; Carlino,
G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.;
Cerrada, M.; Chamizo, M.; Chiarusi, T.; Chang, Y. H.; Chemarin, M.;
Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari,
G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.;
Colino, N.; Costantini, S.; de La Cruz, B.; Cucciarelli, S.; de
Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.;
Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; Denotaristefani,
F.; de Salvo, A.; Diemoz, M.; Dierckxsens, M.; Ding, L. K.; Dionisi,
C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.;
Duran, I.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.;
Engler, A.; Eppling, F. J.; Extermann, P.; Faber, G.; Falagan, M. A.;
Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson,
T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher,
P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta,
C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin,
M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grabosch, H. J.; Grenier,
G.; Grimm, O.; Groenstege, H.; Gruenewald, M. W.; Guida, M.; Guo,
Y. N.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Haller, Ch.;
Hatzifotiadou, D.; Hayashi, Y.; He, Z. X.; Hebbeker, T.; Hervé, A.;
Hirschfelder, J.; Hofer, H.; Hofer, H.; Hohlmann, M.; Holzner, G.;
Hou, S. R.; Huo, A. X.; Ito, N.; Jin, B. N.; Jindal, P.; Jing, C. L.;
Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kantserov, V.; Kaur,
M.; Kawakami, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.;
Kittel, W.; Klimentov, A.; König, A. C.; Kok, E.; Korn, A.; Kopal,
M.; Koutsenko, V.; Kräber, M.; Kuang, H. H.; Kraemer, R. W.; Krüger,
A.; Kuijpers, J.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.;
Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq,
P.; Le Coultre, P.; Le Goff, J. M.; Lei, Y.; Leich, H.; Leiste, R.;
Levtchenko, M.; Levtchenko, P.; Li, C.; Li, L.; Li, Z. C.; Likhoded,
S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.;
Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann,
W.; Ma, W. G.; Ma, X. H.; Ma, Y. Q.; Malgeri, L.; Malinin, A.; Maña,
C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.;
Mele, S.; Meng, X. W.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul,
A.; van Mil, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.;
Monteleoni, B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy,
M.; Nagy, S.; Nahnhauer, R.; Naumov, V. A.; Natale, S.; Napolitano,
M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.;
Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci,
P.; Paramatti, R.; Parriaud, J. -F.; Passaleva, G.; Patricelli, S.;
Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti,
S.; Perret-Gallix, D.; Petersen, B.; Piccolo, D.; Pierella, F.;
Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.;
Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Quartieri, J.;
Qing, C. R.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.;
Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Ravindran,
K. C.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Rewiersma, P.;
Riemann, S.; Riles, K.; Roe, B. P.; Rojkov, A.; Romero, L.; Rosca, A.;
Rosemann, C.; Rosier-Lees, S.; Rosenbleck, C.; Roth, S.; Rubio, J. A.;
Ruggiero, G.; Rykaczewski, H.; Saidi, R.; Sakharov, A.; Saremi, S.;
Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.;
Schmitt, V.; Schoeneich, B.; Schopper, H.; Schotanus, D. J.; Sciacca,
C.; Servoli, L.; Shen, C. Q.; Shevchenko, S.; Shivarov, N.; Shoutko,
V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.;
Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar,
K.; Sulanke, H.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.;
Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.;
Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel
C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Trowitzsch, G.; Tully,
C.; Tung, K. L.; Ulbricht, J.; Unger, M.; Valente, E.; Verkooijen,
H.; van de Walle, R. T.; Vasquez, R.; Veszpremi, V.; Vesztergombi,
G.; Vetlitsky, I.; Vicinanza, D.; Viertel, G.; Villa, S.; Vivargent,
M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.;
Vorobyov, A. A.; Wadhwa, M.; Wang, R. G.; Wang, Q.; Wang, X. L.; Wang,
X. W.; Wang, Z. M.; Weber, M.; van Wijk, R.; Wijnen, T. A. M.; Wilkens,
H.; Wynhoff, S.; Xia, L.; Xu, Y. P.; Xu, J. S.; Xu, Z. Z.; Yamamoto,
J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yang, X. F.;
Yao, Z. G.; Yeh, S. C.; Yu, Z. Q.; Zalite, An.; Zalite, Yu.; Zhang,
C.; Zhang, F.; Zhang, J.; Zhang, S.; Zhang, Z. P.; Zhao, J.; Zhou,
S. J.; Zhu, G. Y.; Zhu, R. Y.; Zhu, Q. Q.; Zhuang, H. L.; Zichichi,
A.; Zimmermann, B.; Zöller, M.; Zwart, A. N. M.
Bibcode: 2005APh....23..411L
Altcode: 2005astro.ph..3472L
The shadowing of high-energy cosmic rays by the Moon has been observed
with a significance of 9.4 standard deviations with the L3 + C muon
spectrometer at CERN. A significant effect of the Earth magnetic field
is observed. Since no event deficit on the east side of the Moon has
been observed, an upper limit at 90% confidence level on the antiproton
to proton ratio of 0.11 is obtained for primary energies around 1 TeV.
Title: Optimal Designs, Mask Manufacture, and Experimental Results
for Shaped Pupil Coronagraphs
Authors: Kasdin, N. J.; Vanderbei, R. J.; Littman, M. G.; Ren, D.;
Carr, M.; Spergel, D. N.
Bibcode: 2004AAS...205.0514K
Altcode: 2004AAS...205..514K; 2004BAAS...36.1343K
Recently, NASA has settled on a coronagraphic ``Terrestrial Planet
Finder'' as its next flagship observatory. This monolithic space
telescope will be equipped with a coronagraph for finding planets. As
a result, the current research being done into coronagraphic concepts
and wavefront control is of great importance. At Princeton, we have
been studying optimal shaped pupils as a means of achieving the needed
high contrast for terrestrial planet detection and characterization. In
this paper, we present our most promising optimal shaped pupil designs,
discuss design tradeoffs, and explore manufacturing sensitivities. We
then present our recent laboratory results using shaped pupils. We
present our most recent pupils manufactured via a variety of methods and
show the imaged point spread functions where we have achieved between
10-6 and 10-7 contrast at better than 5 λ /D. We
gratefully acknowledge the support of the Jet Propulsion Laboratory
of the National Aeronautics and Space Administration for this work.
Title: All-sky extrasolar planet searches with multi-object dispersed
fixed-delay interferometer in optical and near IR
Authors: Ge, Jian; Mahadevan, Suvrath; van Eyken, Julian C.; DeWitt,
Curtis; Friedman, Jerry; Ren, Deqing
Bibcode: 2004SPIE.5492..711G
Altcode:
An all sky survey for extrasolar planets with wide field telescopes,
Sloan 2.5m and WIYN 3.5 telescopes, is being developed. This survey
will use a multi-object version of current Exoplanet Tracker (ET)
Doppler instrument commissioned at the KPNO 2.1m telescope in June
2004. This instrument is based on dispersed fixed-delay interferometer,
a combination of a Michelson interferometer with a moderate dispersion
spectrometer (Ge 2002). This custom designed instrument (f/2 optics)
has a wavelength coverage of ~ 600 Å with a 4kx4k CCD camera at a
spectral resolution of R = 5,000. The measured instrument detection
efficiency, including telescope, fiber, interferometer, spectrometer
and detector losses, has ~ 18% (or 50% throughput from the fiber
input to the detector), more than 4 times higher than current echelle
instruments being used for planet detection. ET has been able to
routinely obtain S/N ~ 80 data for V ~ 8 mag. stars in 15 min exposures
with the KPNO 2.1m. It allows us to reach ~ 3.5 m/s Doppler precision
for radial velocity (RV) stable stars with S/N ~ 120 per pixel. It
also allows us to confirm an exoplanet curve of HD 130322 (V = 8.05)
with rms Doppler error of 12.3 m/s (preliminary results). We are in
the middle of design of two prototype multiple object RV instrument
for the Sloan and WIYN telescopes, which are capable of observing 50
stars (V ~ 8-13) in a single exposure. We plan to conduct the all sky
survey for planets around ~ 1 millions of stars with Sloan starting
in 2008. Our goal is to identify ~ 100,000 extrasolar planets with ~
1,000 solar analogues through this survey.
Title: Results from upgrades to the radial velocity instrument, ET,
at the KPNO 2.1 m
Authors: van Eyken, Julian C.; Ge, Jian; Mahadevan, Suvrath; DeWitt,
Curtis; Friedman, Jerry; Finnerty, Padraic; Ren, Deqing; Zugger, Mike
Bibcode: 2004SPIE.5492..445V
Altcode:
A radial velocity (RV) survey instrument, Exoplanet Tracker (ET), has
been commissioned at the Kitt Peak 2.1m telescope. It is a fiber-fed,
fixed-delay Michelson interferometer followed by a medium resolution
volume phase holographic spectrograph (operating at ~5000) for the
visual band, and is planned to be opened to the public for RV related
research in 2005. Since 2002 the measured total throughput of ET from
above the atmosphere to the detector has been improved to about 18%
(or 50% for the instrument itself from the fiber input to the detector),
~5 times higher than the current cross-dispersed echelle spectrometers
for Doppler planet searches. We present new preliminary results from our
improved version of ET, with 600 Angstrom wavelength coverage, showing
RV measurements for HD 130322 (V=8.05), a known planet-bearing star,
using 15 min exposures. A best short-term Doppler precision of 2.9
m/s has been achieved with this new instrument. We will start a pilot
planet search of around 500 V=8--9 mag. stars with the 2.1m telescope
in the Spring of 2005, and a multiple object RV feasibility study will
also be conducted at the Sloan 2.5m wide field telescope in Spring 2005.
Title: An Image Slicer Integral Field Unit with Diffraction-limited
Performance for Three-Dimensional Imaging Spectroscopy
Authors: Ren, Deqing; Ge, Jian
Bibcode: 2004PASP..116...46R
Altcode:
We have designed and constructed an advanced image slicer (AIS)
integral field unit (IFU). The IFU employs an all-mirror design and
will be installed in the Penn State near-IR Imager and Spectrograph
(PIRIS) for three-dimensional integral field spectroscopy at various
astronomical telescopes. Using the AIS technique, the slicer IFU can
preserve the telescope's focal ratio and pupil (both position and size)
while maximizing the packing efficiency for three-dimensional data on
the detector. Compared to other existing AIS IFU designs, our design,
which uses monolithic optical components for both pupil and field mirror
arrays, provides a convenient engineering solution for manufacturing,
using the state-of-the-art diamond-turning machines and alignment
of the IFU optics. Our slicer mirror array was also manufactured by
diamond turning, with all the mirrors simultaneously machined, which
also simplifies the procedure for the manufacture and the assembly of
the mirrors. We present the IFU optical description, component test
results, and overall IFU system performance. We also discuss possible
science applications using the IFU.
Title: HXMT satellite for space hard X-ray observation
Authors: Wu, Y. P.; Ren, D. H.; You, Z.
Bibcode: 2004AdSpR..34.2667W
Altcode:
In this paper, the Hard X-ray Modulation Telescope mission is
introduced. Its primary objective is to perform the hard X-ray all sky
survey of high resolution and high sensitivity. The expected angular
resolution and position accuracy of the satellite are better than 10
' and 2 ', respectively. The preliminary mission
design is analyzed. And a new attitude subsystem scheme is presented to
meet the high precision demand of attitude determination. A conclusion
is drawn that the mission design is feasible. The possible launch of
it will significantly advance the astrophysical study.
Title: New Results from the RV instrument, Exoplanet Tracker, at
the KPNO 2.1m
Authors: DeWitt, C.; Ge, J.; Mahadevan, S.; Van Eyken, J.; Ren, D.;
Friedman, G.
Bibcode: 2003AAS...203.1702D
Altcode: 2003BAAS...35.1234D
This poster presents preliminary results from the commissioning of
the radial velocity survey instrument, Exoplanet Tracker (ET), at the
Kitt Peak 2.1m telescope. ET is a fiber-fed, fixed-delay Michelson
interferometer followed by a medium resolution (R=10000) volume phase
holographic spectrograph for the visual band. It will be open to
the public for RV related research. ET's total throughput from above
the atmosphere to the detector is about 30%, 5-10 times higher than
the current cross-dispersed echelle spectrometers for Doppler planet
searches. In this instrument, Doppler shifts are tracked by measuring
phase changes in the interference fringes of the stellar lines against
the interferometer comb, instead of measuring line shifts directly
as in the echelle approach.