Author name code: marmolino ADS astronomy entries on 2022-09-14 author:"Marmolino, Ciro" ------------------------------------------------------------------------ Title: Phase Differences and Gains between Intensity and Velocity in Low-Degree Acoustic Modes Measured by SOHO Authors: Jiménez, Antonio; Roca Cortés, Teodoro; Severino, Giuseppe; Marmolino, Ciro Bibcode: 1999ApJ...525.1042J Altcode: Helioseismic instruments aboard SOHO are making possible a more accurate way of investigating the internal structure of the Sun. Making use of the different techniques and characteristics of these instruments, it is possible to measure solar oscillations as variations of the photospheric velocity (GOLF, MDI) or as irradiance and radiance fluctuations (VIRGO, MDI). Among the other advantages of observing solar oscillations simultaneously with different instruments and techniques, the study of velocity and irradiance measurements provides information on nonadiabatic effects in the radiatively cooled solar atmosphere. The thermodynamical properties of the atmosphere determine a phase shift between intensity and velocity (downward positive) oscillations of -90° in the case of an adiabatic atmosphere. Here we compute the phase differences and gains between intensity and velocity acoustic modes measured by SOHO to quantify the nonadiabatic degree of the solar atmosphere. After correcting the observed phase differences of the solar background influence, we find not exactly an adiabactic behavior, but close to it. Finally, we compare our results with three different theoretical models of the solar atmosphere, finding the best agreement with a model that includes turbulent pressure associated with convection and fluctuations of the superadiabatic temperature gradient.

Based on observations with the VIRGO, GOLF, and MDI instruments on board SOHO. Title: Intensity-velocity phase relations in the l - ν diagram Authors: Masiello, G.; Marmolino, C. Bibcode: 1998MmSAI..69..619M Altcode: No abstract at ADS Title: A Review of Intensity-Velocity Phase Relations in the Solar Atmosphere: Observations Authors: Masiello, G.; Marmolino, C.; Straus, Th. Bibcode: 1998ESASP.418..261M Altcode: 1998soho....6..261M It is well known that the observation of the frequencies of solar oscillations is a powerful diagnostic of the solar interior. In the same way, the Intensity-Velocity (I - V) phase differences are more and more becoming an efficient tool to investigate the dynamics of the solar atmosphere. Here we present an up-to-date review of observed phase differences PhiI-V, as function of temporal frequency (nu), of degree (l), and of height in the atmosphere (h). The workers active in this field use different conventions and definitions. This heterogeneity does not help in the interpretation of an observable which has not yet been completely understood on theoretical grounds. We suggest to use the notation which attributes positive values to the phase difference when the intensity perturbation leads the velocity perturbation, taken positive away from the Sun. In our opinion, this choice is the more convenient when comparing observed and theoretical phase differences. The collection of the observed results in a ''box'', with edges nu, l, and h, reveals an almost coherent scenario and allows to state what is missing from an observational point of view. For example, are still missing, at every height in the atmosphere, observations of phase differences for intermediate l values (~4 <= l <= ~100), while some depths in the atmosphere are little explored. Different phase regimes can be identified in the l - ν diagram and it is possible to follow their behavior with the height in the atmosphere. Since, up to now, phase differences have been discussed only in terms of atmospheric oscillations, the comparison between theory and observation is still in its infancy and it is not yet complete the identification of the different phase regimes with different dynamic and atmospheric phenomena. Title: Phase spectra seen from space Authors: Straus, Th.; Deubner, F. -L.; Fleck, B.; Marmolino, C.; Severino, G.; Tarbell, T. Bibcode: 1998IAUS..185..455S Altcode: We discuss preliminary results of a study of the dynamics of the solar atmosphere including a first space based investigation of k-omega phase difference spectra between velocity and intensity perturbations. The data, including simultaneous line shift, line depth, and continuum intensity measurements at disk center, have been obtained from a MDI time series in its high resolution mode. Line depth and continuum intensity are used to calculate the line intensity which is the more frequently used parameter in phase difference studies. We compare the results to ground based observations. Title: K-ϖ Phase Spectra Obtained from Space Authors: Straus, Th.; Fleck, B.; Severino, G.; Deubner, F. -L.; Marmolino, C.; Tarbell, T. Bibcode: 1998ESASP.417..293S Altcode: 1998cesh.conf..293S No abstract at ADS Title: The Magneto-Optical Filter in Napoli: Perspectives and Test Observations Authors: Moretti, P. F.; Severino, G.; Cauzzi, G.; Reardon, K.; Straus, T.; Cacciani, A.; Marmolino, C.; Oliviero, M.; Smaldone, L. A. Bibcode: 1997ASSL..225..293M Altcode: 1997scor.proc..293M An observing station based on the Magneto-Optical-Filter (MOF) technology is being installed at Osservatorio Astronomico di Capodimonte, in Napoli. In this paper, the main characteristics and goals of this new instrument are discussed, and several velocity and magnetic observations from a test campaign are shown. Title: Active region effects on solar irradiance at NA I D lines Authors: Marmolino, C.; Oliviero, M.; Severino, G.; Smaldone, L. A. Bibcode: 1997A&AS..125..381M Altcode: The possibility to detect solar oscillations in the low frequency domain depends crucially on the power contrast among the oscillation signal and other time dependent signals in the same frequency range. The signal to noise ratio is increased by our ability to understand and remove solar sources of noise. In measurements of the mean Doppler velocity shift of the integrated solar disk, the solar noise has a line component spectrum with a major peak at 13.1 days, and a second less prominent peak at 27.2 days. Active region modulation is believed almost completely responsible for this signal. We develop simulations of the flux and velocity fluctuations produced by different solar active region distributions, based on an analytical description of their action. From a grid of models of active regions and from their spatial distribution over the disk, we calculate the synthetic flux profile in the Na I D1 line and determine the velocity measure of a resonance spectrometer. Our velocity results are compared with the offset velocities from the IRIS network. There is a rather good agreement between the observed and computed velocities, and the plage contribution to the noise appears to be dominant. The simulation allows to test calibration procedures and to study the effect on the spurious velocities of different parameters, such as the intensity thresholds used to determine the areas of spots and plages, and the contrast of the active regions. In particular, we find that the inclusion of intrinsic line shifts in plages can change strongly both the amplitude and the shape of the simulated signal, and then may be an important source of uncertainty for the simulation. Title: Preface Authors: Cauzzi, G.; Marmolino, C. Bibcode: 1997MmSAI..68..359C Altcode: No abstract at ADS Title: The ARGO full Coverage Detector Authors: Bacci, C.; Bartoli, B.; Barone, F.; Dai, Behzhong; Bernardini, P.; Calloni, E.; Cardarelli, R.; Catalanotti, S.; Cavaliere, A.; Cessaroni, F.; Xu, Chunxian; Creti, P.; Banzengluobu; D'Ettorre Pizaaoli, B.; De Vincenzi, M.; Di Sciascio, G.; Cai, Dong; Grado, A.; Yu, Guangce; Kuang, Haohuai; Jia, Hunayu; He, Huilin; He, Huihai; Guo, Hongwei; Lee, Huidong; Iacovacci, M.; Iucci, N.; Li, Jinyu; Le, Meng; Marmolino, C.; Manearella, G.; Mari, S. M.; Martello, D.; Morselli, A.; Milano, L.; Oliviero, M.; PAdovani, P.; Panareo, M.; Parisi, M.; Shen, Peiruo; Pistilli, P.; Saavedra, O.; Santonico, R.; Severino, G.; Sparvolli, R.; Stanescu, C.; Storini, M.; Surdo, A.; Vernetto, S.; Villoresi, G.; Zhao, Xin; Zhang, Xueyao; Jiang, Yinlin; Chen, Yongzhong; Tan, Youheng; Fu, Yu; Feng, Zhenyong Bibcode: 1997ICRC....5..265B Altcode: 1997ICRC...25e.265B No abstract at ADS Title: The inconstant Sun. Proceedings. 2nd Napoli Thinkshop on Physics and Astrophysics, Napoli (Italy), 18 Mar 1996. Authors: Cauzzi, G.; Marmolino, C. Bibcode: 1997MmSAI..68..355C Altcode: This Thinkshop addresses the problem of the contribution that solar physics can give to modern physics and astrophysics. Title: ARTHEMIS: The Archive Project for the IPM and THEMIS Authors: Reardon, K.; Severino, G.; Cauzzi, G.; Gomez, M. T.; Straus, T.; Russo, G.; Smaldone, G.; Marmolino, C. Bibcode: 1997ASPC..118..398R Altcode: 1997fasp.conf..398R We describe the plan for ARTHEMIS, the italian archive for THEMIS, from the point of view of the prospective users of the archive. This archive is designed to store the data from the Italian Panoramic Monochromator (IPM) instrument installed on THEMIS as well as the full-disk images obtained by the telescope. We break the expected users down into seven categories: a) prospective IPM users; b) campaign planners; c) data analysts, d) external collaborators; e) instrument monitors, f) archival observers; and g) the general public. Title: ARTHEMIS: The archive project for the Italian Panoramic Monochromator Authors: Reardon, K.; Severino, G.; Cauzzi, G.; Gomez, M. T.; Straus, T.; Russo, G.; Smaldone, L. A.; Marmolino, C. Bibcode: 1997MmSAI..68..499R Altcode: No abstract at ADS Title: Simultaneous Doppler and magnetic solar maps from a MOF installed at the Osservatorio di Capodimonte Authors: Cacciani, A.; Marmolino, C.; Moretti, P. F.; Oliviero, M.; Severino, G.; Smaldone, L. A. Bibcode: 1997MmSAI..68..467C Altcode: No abstract at ADS Title: Active regions effects on global oscillation measurements. Authors: Marmolino, C.; Oliviero, M.; Severino, G.; Smaldone, L. A. Bibcode: 1996joso.proc..160M Altcode: No abstract at ADS Title: Magnetic Noise Simulations in Velocity Authors: Marmolino, C.; Oliviero, M.; Severino, G.; Smaldone, L. A. Bibcode: 1995ESASP.376b.407M Altcode: 1995help.confP.407M; 1995soho....2..407M No abstract at ADS Title: Phases and amplitudes of acoustic-gravity waves. 2: The effects of reflection Authors: Marmolino, C.; Severino, G.; Deubner, F. -L.; Fleck, B. Bibcode: 1993A&A...278..617M Altcode: We study wave reflection caused by the temperature stratification of the solar atmosphere, assumed to be a succession of two layers of different temperatures and radiative decay times. Considering waves which propagate energy upward in the atmosphere, we compute the complex amplitude reflection and transmission coefficients and investigate the effects that reflection introduces on the phases of acoustic-gravity waves. In the evanescent region of the kx - omega diagram, between the Lamb waves and the acoustic cut-off frequency, the reflection coefficient is small, in particular zero on the fundamental mode. Therefore, in this region, the reflected wave has a small amplitude and its superposition to the incident wave does not affect the latter in a significant way. In particular, the T - V phase differences of the total wave are very similar to those of the incident wave. Furthermore, a heruisitic formula is presented which describes the observed coexistence of two different phase regimes between velocity and intensity oscillations in the evanescent area above the fundamental mode. Title: Solar astronomy: the GOLF experiment on board of SOHO Authors: Severino, G.; Gomez, M. T.; Andretta, V.; Marmolino, C. Bibcode: 1993MmSAI..64..790S Altcode: No abstract at ADS Title: The center-to-limb variations of four Ca i lines in the photospheric spectrum at λ6500 Authors: Ambruoso, P.; Marmolino, C.; Gomez, M. T.; Severino, G. Bibcode: 1992SoPh..141...35A Altcode: We study the center-limb (CL) variation of the average profiles of four Ca I lines near λ6500 and compare these observations with synthetic data obtained from several line formation models having different thermal structures, line parameters, LTE and non-LTE conditions, and micro and macroturbulence values, to assess the formation characteristics of our Ca I lines in the solar photosphere. Title: Phases and amplitudes of acoustic-gravity waves. I - Upward and downward solutions Authors: Marmolino, C.; Severino, G. Bibcode: 1991A&A...242..271M Altcode: A study is presented of the phases and amplitudes of acoustic-gravity waves in the kx-omega diagram. Waves which propagate energy both upward and downward in the solar atmosphere are considered. The wave model considers linear perturbations in a compressible medium assumed to be a perfect gas stably stratified at uniform temperature and radiatively damped. The kx-omega diagrams are also displayed for the temperature and pressure amplitudes relative to velocity. The results from the model are discussed and compared with recent observations of the phase relations between velocity and brightness oscillations. Title: Dynamics of the solar atmosphere. IV - Evanescent waves of small amplitude Authors: Deubner, F. -L.; Fleck, B.; Marmolino, C.; Severino, G. Bibcode: 1990A&A...236..509D Altcode: The phase spectra of velocity and brightness perturbations in the quiet photosphere have been studied in the evanescent domain of the k-omega diagram. A regime of low-amplitude evanescent motions, occupying a large sector of the diagnostic diagram bordered by the Lamb and the fundamental mode, has been discovered. This regime forms a continuum in the k-omega plane, in contrast to the 5-min oscillations. Beyond the fundamental mode, it extends to much higher frequencies in between the power ridges of the resonant p-modes. It is suggested that the observed V-I phase is characteristic of evanescent waves, whose progressive part carries energy downward, and that a continuum of such waves is produced through scattering of ordinary resonant p-modes at higher levels in the atmosphere. Title: On the 5-MINUTE Photospheric Oscillation and its Modeling Authors: Marmolino, C.; Severino, G. Bibcode: 1990IAUS..138..251M Altcode: No abstract at ADS Title: Wave Behavior in the Solar Photosphere - a Comparison of Theory and Observation Authors: Marmolino, Ciro; Stebbins, Robin T. Bibcode: 1989SoPh..124...23M Altcode: We report detailed comparisons between theoretical and empirical eigenfunctions of velocity and intensity for the 5-min modes in the photosphere. The comparison process is accomplished by obtaining synthetic profiles of the FeI λ5434 Å line in the presence of waveforms given by dynamical calculations and then applying a common procedure of reduction both to the observed and to the synthetic data. For the velocity waveforms, our results show a general agreement between theory and observations together with some systematic differences; in particular the theory systematically underestimates the observations in the low photosphere. These systematic differences are stressed by the intensity results since both the computed amplitudes and phases appear to be wrong in the deeper layers. Title: The signature of the 5-minute photospheric oscillation on the solar spectral line profiles Authors: Marmolino, C.; Severino, G. Bibcode: 1989MmSAI..60..181M Altcode: No abstract at ADS Title: Observation and Interpretation of Photospheric Line Asymmetry Changes near Active Regions Authors: Keil, S. L.; Roudier, Th.; Cambell, E.; Koo, B. C.; Marmolino, C. Bibcode: 1989ASIC..263..273K Altcode: 1989ssg..conf..273K No abstract at ADS Title: The 5-minute oscillation in the solar photosphere - Theoretical behaviour versus observations Authors: Marmolino, C.; Stebbins, R. T. Bibcode: 1989MmSAI..60...71M Altcode: Calculations are used to explore how theoretical waveforms for the five-minute solar oscillation reproduce the observed behavior of the solar Fe I 5434 A line. Comparison of theoretical and empirical velocity eigenfunctions shows some systematic differences in a framework of general agreement. The theory systematically underestimates the observations in both amplitude and phase shift in the low photosphere; the differences between the various theoretical treatments is much smaller than the difference between theory and observation. The intensity agreement is poor, with the theoretical treatments again differing much less with each other than with observation. These results are evidence for systematic problems with the assumptions involved in the calculation of the waveforms pertaining to the deeper layers of the photosphere. Title: Fe II lines in the presence of photospheric oscillations Authors: Marmolino, C.; Roberti, G.; Severino, G. Bibcode: 1988ASSL..138..217M Altcode: 1988pffl.proc..217M; 1988IAUCo..94..217M The synthesis of the Fe II 6516 A line in the solar photosphere in the presence of granulation and five-minute oscillation is described. The asymmetry of the spatially resolved profiles in the presence of granulation is much stronger than that of the mean, unresolved profile. There is a blueshift of the spatially averaged line profile corresponding to a velocity of 360 m/s in the center of gravity. The line bisector produced by the five-minute oscillation are plotted as a function of time. When both granulation and five-minute oscillation are present, the general behavior of the spatially averaged line bisector vs. time is just the temporal fluctuation of the spatially mean C-shape due to the granulation. When granulation is present, the blue flank in the line profiles oscillates with a velocity amplitude lower than the red flank does. Title: Temporal variations of solar spectral line profiles induced by the 5-minute photospheric oscillation Authors: Gomez, M. T.; Severino, G.; Marmolino, C.; Roberti, G. Bibcode: 1987A&A...188..169G Altcode: The authors simulated the variations induced by the 5 min photospheric oscillation on the line profiles. They found that a phase lag of the order of 150 degree between temperature and velocity wave perturbations can explain the observed differences between the oscillations of the line flanks at residual intensity levels I/Ic < 0.7. Such a phase relation in the 5 min oscillation differs from that of the adiabatic case in which the temperature and pressure fluctuations are 90 degrees out of phase with respect to the velocity. It is shown that a simple model of radiative damping in the solar photosphere can produce the required phase lag between temperature and velocity. Finally, it is also shown that the granulation can affect differentially the oscillations of the line flanks. This effect, however, does not fit the observed behaviour of the flank oscillations. Title: Effects of acoustic and gravity waves on the curve of growth Authors: Marmolino, C. Bibcode: 1987SoPh..112..211M Altcode: Unresolved motions, or `microturbulence', play a very important role in determining the Doppler width of the line-absorption coefficient. The concept of microturbulence was introduced because observed solar and stellar lines are broader than is explicable within the framework of other line-broadening mechanisms. By constructing a curve-of-growth in the presence of a dynamical model for simple acoustic and gravity waves, this paper evaluates the errors introduced by the use of kinematic models for line-broadening (microturbulence) into the determinations of non-thermal velocity fields and element abundances. Distinct differences between gravity and acoustic waves are apparent in the trend of the line asymmetry with the excitation potential as well as in the magnitude of the errors introduced by the temperature and pressure variations associated with the velocity field. Title: Broadening and shift of Fe i lines perturbed by atomic hydrogen Authors: Gomez, M. T.; Marmolino, C.; Roberti, G.; Severino, G. Bibcode: 1987SoPh..112..227G Altcode: The broadening and shift parameters for a number of FeI lines perturbed by atomic hydrogen are computed using the interatomic potential due to Hindmarsh et al. (1967, 1970). It is also shown that the rms radius and the effective radius of the radiating atom, which determine the force constants in the interatomic potential, can be simply related each other, depending on the orbital quantum number of the atomic level. Title: Line asymmetries and shifts in the presence of granulation and oscillations: The CLV of the K i 7699 resonance line Authors: Marmolino, C.; Roberti, G.; Severino, G. Bibcode: 1987SoPh..108...21M Altcode: We study the effects of both the solar granulation and short-period oscillations on the solar profile of the KI 7699 resonance line and its center-to-limb variations. Title: On the Differences between Line Bisectors in Quiet and Active Sun Authors: Marmolino, C.; Roberti, G.; Severino, G. Bibcode: 1987rfsm.conf...30M Altcode: The asymmetry and shift of solar lines show systematic variations between quiet and active regions. Marmolino et al. (1984, 1986) studied the effects produced by photospheric motions (waves and granulation) on the K I 7699 Å line in the quiet Sun. In this paper the authors extend this study to the synthesis of line bisectors in plages. Title: Diagnostics for Propagating Waves in the Solar Photosphere Authors: Keil, Stephen L.; Marmolino, Ciro Bibcode: 1986ApJ...310..912K Altcode: The effects of pure acoustic waves of different frequencies on a number of Fe I lines formed in the photosphere are investigated. A dynamical model of the waves which considers velocity, temperature, and pressure fluctuations as functions of time is used to compute the line profiles. The extent to which the waves cause the lines to fluctuate, the time-averaged properties of the line profiles, and the measurability of vertical phase differences are all determined as functions of the frequency of the propagating wave. It is concluded that there is no intrinsic radiative limit, for frequencies of current observational interest, on ability to measure phase differences. The asymmetry induced by the propagation of acoustic waves in the photosphere is found to depend on the frequency of the waves. Acoustic waves contribute only marginally to line broadening. Title: The effects of acoustic-gravity waves on the K i 7699 line Authors: Severino, G.; Roberti, G.; Marmolino, C.; Gomez, M. T. Bibcode: 1986SoPh..104..259S Altcode: We examine the effects of acoustic-gravity waves with long and short periods on the solar profile of the K I7699 line using a dynamic model of line formation. Title: The Effects of Acoustic Waves on the Curve of Growth Authors: Marmolino, C. Bibcode: 1986BAAS...18Q.663M Altcode: No abstract at ADS Title: Line Asymmetries and Shifts in Presence of Granulation and Oscillations - the CLV of the KI7699 Resonance Line Authors: Marmolino, C.; Roberti, G.; Severino, G. Bibcode: 1985tphr.conf...89M Altcode: No abstract at ADS Title: Line asymmetries and shifts in presence of granulation and oscillations: the CLV of the K I 7699 resonance line. Authors: Marmolino, C.; Roberti, G.; Severino, G. Bibcode: 1985MPARp.212...89M Altcode: The authors study the effects of both the solar granulation and a monochromatic acoustic-gravity wave on the solar profile of the K I 7699 resonance line and its center-to-limb variations (CLV). Title: The response of the line KI 7699 to the solar oscillations Authors: Marmolino, C.; Roberti, G.; Severino, G.; Vazquez, M.; Woehl, H. Bibcode: 1984ESASP.220..191M Altcode: 1984ESPM....4..191M The time behavior of the KI 7699 line profile in presence of acoustic-gravity waves with periods of 300, 180, and 30 sec was studied. The response of the line to the waves depends strongly on the period and is not linear for the 30 sec wave. The height increase of the amplitude in the longer period waves explains the observed anticorrelation between line asymmetry and line core shift. The time averaged profile for the 30 sec wave has a red shifted line core. This could account for the lowest part of the C shaped solar bisectors. Title: CA II K emission diagnostics. I - The widths and the strengths in a one-dimensional model Authors: Marmolino, C.; Severino, G. Bibcode: 1983A&A...127...33M Altcode: The authors modeled the widths and the strengths of the Ca II K emission from a one-dimensional atmosphere in terms of a limited set of parameters. Partial frequency redistribution (PRD) in the scattering process was correctly accounted for. The emission characteristics depend generally on several model parameters. However the dependence on chromospheric microturbulence appears to fit easily the observed behaviour of the K2 peak separation, W2, and of the full width at half-maximum, W0. The authors remark that emission in the core of the K line can occur as a PRD effect, without any chromospheric temperature rise, and discuss some implications of this event. Title: Detection of Propagating Waves in the Solar Photosphere Authors: Keil, S. L.; Marmolino, C. Bibcode: 1983BAAS...15Q.971K Altcode: No abstract at ADS Title: Magnetic Fine-Structures and Granular Velocities Authors: Caccin, B.; Falciani, R.; Gomez, M. T.; Marmolino, C.; Roberti, G.; Severino, G.; Smaldone, L. A. Bibcode: 1981SSRv...29..373C Altcode: In the last years we have gained some experience in the diagnostics of small-scale structures, both on the interpretative and on the observational point of view. We report here the conclusions and the suggestions for future developments attained in two main fields of interest. Title: The third central moment of photospheric lines as a measure of velocity gradients and line shifts Authors: Marmolino, C.; Severino, G. Bibcode: 1981A&A...100..191M Altcode: The significance of the third central moment (M3) of photospheric line profiles as an indicator of velocity, temperature and pressure perturbations is analyzed. A linear inversion method is applied to the third central moments of a set of synthetic lines computed using the temperature structures of the B2 and D2 models of Altrock and Musman (1976) for the granular and intergranular atmospheres, respectively, in order to derive mean photospheric velocity gradients. It is found that for data taken with infinite spatial resolution, M3 is a nearly linear measure of the velocity gradients, whereas at finite resolution it is essentially determined by the different weights of the shifted granular and intergranular line components. Results also suggest a means of disentangling velocity gradients and the horizontal integration of inhomogeneities. Title: On the retrieval of velocity gradients from photospheric line asymmetries - A linearized approach Authors: Caccin, B.; Marmolino, C. Bibcode: 1980A&A....83...73C Altcode: The first-order effects of a velocity field on the asymmetry of Fraunhofer lines are analyzed and a method for recovering the velocity gradient from the observed asymmetries is described. The method - which does not require the concept of formation depth - is applied to the inversion of synthetic data; the results obtained show that it has the properties of stability and sensitivity necessary for working in practice within a fairly large range of photospheric velocities (up to the order of the Doppler width of the lines). Title: Determinazione dei gradienti di velocità nella fotosfera solare dalle asimmetrie delle righe di Fraunhofer: un approccio lineare. Authors: Caccin, B.; Marmolino, C. Bibcode: 1979RSAI...22..146C Altcode: No abstract at ADS Title: Response functions and contribution functions of photospheric lines. Authors: Caccin, B.; Gomez, M. T.; Marmolino, C.; Severino, G. Bibcode: 1977A&A....54..227C Altcode: An attempt is made to obtain the response function (RF) of a photospheric Fraunhofer line by solving the equation of radiative transfer in LTE using an appropriate perturbation method. A first-order expression for the RF is derived with which effects of arbitrary perturbations in thermodynamic quantities or velocity-field parameters on emergent line intensity can be evaluated. Perturbations considered to be amenable to such treatment include line-opacity Doppler shifts due to velocity fields, microturbulence variations, and temperature variations at constant electron density. Some examples of RFs for photospheric lines are presented, and an attempt is made to define the contribution function (CF) of a line depression in full analogy with that of the emergent intensity. It is noted that a CF should not be employed in place of the appropriate RF to predict the sensitivity of a Fraunhofer line to a perturbation at a given depth.