ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-26-2961-2008 Diagnostics of active and eruptive prominences through hydrogen and helium lines modelling Labrosse N. 1 3 Vial J.-C. 2 Gouttebroze P. 2 Institute of Mathematical and Physical Sciences, University of Wales Aberystwyth, UK Institut d'Astrophysique Spatiale, CNRS – Université Paris XI, Orsay, France now at: Department of Physics and Astronomy, University of Glasgow, UK 15 10 2008 26 10 2961 2965 Copyright: © 2008 N. Labrosse et al. 2008 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/26/2961/2008/angeo-26-2961-2008.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/26/2961/2008/angeo-26-2961-2008.pdf

In this study we show how hydrogen and helium lines modelling can be used to make a diagnostic of active and eruptive prominences. One motivation for this work is to identify the physical conditions during prominence activation and eruption. Hydrogen and helium lines are key in probing different parts of the prominence structure and inferring the plasma parameters. However, the interpretation of observations, being either spectroscopic or obtained with imaging, is not straightforward. Their resonance lines are optically thick, and the prominence plasma is out of local thermodynamic equilibrium due to the strong incident radiation coming from the solar disk. In view of the shift of the incident radiation occuring when the prominence plasma flows radially, it is essential to take into account velocity fields in the prominence diagnostic. Therefore we need to investigate the effects of the radial motion of the prominence plasma on hydrogen and helium lines. The method that we use is the resolution of the radiative transfer problem in the hydrogen and helium lines out of local thermodynamic equilibrium. We study the variation of the computed integrated intensities in H and He lines with the radial velocity of the prominence plasma. We can confirm that there exist suitable lines which can be used to make a diagnostic of the plasma in active and eruptive prominences in the presence of velocity fields.

 References Anzer, U. and Heinzel, P.: The energy balance in solar prominences, \aap, 349, 974–984, 1999. Delaboudiniere, J.-P., Artzner, G E., Brunaud, J., Gabriel, A H., Hochedez, J F., Millier, F., Song, X Y., Au, B., Dere, K P., Howard, R A., Kreplin, R., Michels, D J., Moses, J D., Defise, J M., Jamar, C., Rochus, P., Chauvineau, J P., Marioge, J P., Catura, R C., Lemen, J R., Shing, L., Stern, R A., Gurman, J B., Neupert, W M., Maucherat, A., Clette, F., Cugnon, P., and van Dessel, E L.: EIT: Extreme-Ultraviolet Imaging Telescope for the SOHO Mission, \solphys, 162, 291–312, 1995. Engvold, O., Hirayama, T., Leroy, J L., Priest, E R., and Tandberg-Hanssen, E.: Hvar Reference Atmosphere of Quiescent Prominences, in: Dynamics of Quiescent Prominences. Proceedings of I.A.U. Colloquium #117, 25–29 September 1989, edited by: Ruzdjak, V. and Tandberg-Hanssen, E.; Publisher, Springer-Verlag, New York, 1990, p. 294, 1990. Gontikakis, C., Vial, J.-C., and Gouttebroze, P.: Emission of hydrogen lines by moving solar prominences., \aap, 325, 803–812, 1997a. Gontikakis, C., Vial, J.-C., and Gouttebroze, P.: Spectral diagnostics for eruptive prominences, \solphys, 172, 189–197, 1997b. Gouttebroze, P., Heinzel, P., and Vial, J.-C.: The hydrogen spectrum of model prominences, \aaps, 99, 513–543, 1993. Gunár, S., Heinzel, P., Schmieder, B., Schwartz, P., and Anzer, U.: Properties of prominence fine-structure threads derived from SOHO/SUMER hydrogen Lyman lines, \aap, 472, 929–936, \doi10.1051/0004-6361:20077785, 2007. Heinzel, P.: The Fine Structure of Solar Prominences, in: The Physics of Chromospheric Plasmas, edited by: Heinzel, P., Dorotovi\v c, I., and Rutten, R J., vol. 368 of Astronomical Society of the Pacific Conference Series, 271 pp., 2007. Heinzel, P. and Rompolt, B.: Hydrogen emission from moving solar prominences, \solphys, 110, 171–189, 1987. Kohl, J L. and Withbroe, G L.: EUV spectroscopic plasma diagnostics for the solar wind acceleration region, \apj, 256, 263–270, \doi10.1086/159904, 1982. Krall, J. and Sterling, A C.: Analysis of Erupting Solar Prominences in Terms of an Underlying Flux-Rope Configuration, \apj, 663, 1354–1362, \doi10.1086/518400, 2007. Kucera, T A. and Landi, E.: An Observation of Low-Level Heating in an Erupting Prominence, \apj, 673, 611–620, \doi10.1086/523694, 2008. Labrosse, N. and Gouttebroze, P.: Formation of helium spectrum in solar quiescent prominences, \aap, 380, 323–340, \doi10.1051/0004-6361:20011395, 2001. Labrosse, N., Vial, J C., and Gouttebroze, P.: The Helium Spectrum in Erupting Solar Prominences, Solar Active Regions and 3D Magnetic Structure, 26th meeting of the IAU, Joint Discussion 3, 16–17 August 2006, Prague, Czech Republic, JD03, #47, 3, 2006. Labrosse, N., Gouttebroze, P., and Vial, J.-C.: Effect of motions in prominences on the helium resonance lines in the extreme ultraviolet, \aap, 463, 1171–1179, \doi10.1051/0004-6361:20065775, 2007a. Labrosse, N., Gouttebroze, P., and Vial, J.-C.: Spectral Diagnostics of Active Prominences, in: The Physics of Chromospheric Plasmas, edited by: Heinzel, P., Dorotovi\v c, I., and Rutten, R J., vol. 368 of Astronomical Society of the Pacific Conference Series, 337 pp., 2007b.