0482508 - ASÚ 2018 RIV US eng J - Článek v odborném periodiku
Falewicz, R. - Radziszewski, K. - Rudawy, P. - Berlicki, Arkadiusz
Time Variations of Observed H alpha Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare.
Astrophysical Journal. Roč. 847, č. 2 (2017), 84/1-84/14. ISSN 0004-637X. E-ISSN 1538-4357
Grant CEP: GA ČR(CZ) GA16-18495S
Grant ostatní: EC(XE) 606862
Program: FP7
Institucionální podpora: RVO:67985815
Klíčová slova: Sun * chromosphere * corona
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.551, rok: 2017

We compare time variations of the Ha and X-ray emissions observed during the pre-impulsive and impulsive phases of the C1.1-class solar flare on 2013 June 21 with those of plasma parameters and synthesized X-ray emission from a 1D hydrodynamic numerical model of the flare. The numerical model was calculated assuming that the external energy is delivered to the flaring loop by nonthermal electrons (NTEs). The Ha spectra and images were obtained using the Multi-channel Subtractive Double Pass spectrograph with a time resolution of 50.ms. The X-ray fluxes and spectra were recorded by RHESSI. Pre-flare geometric and thermodynamic parameters of the model and the delivered energy were estimated using RHESSI data. The time variations of the X-ray light curves in various energy bands and those of the Ha intensities and line profiles were well correlated. The timescales of the observed variations agree with the calculated variations of the plasma parameters in the flaring loop footpoints, reflecting the time variations of the vertical extent of the energy deposition layer. Our result shows that the fast time variations of the Ha emission of the flaring kernels can be explained by momentary changes of the deposited energy flux and the variations of the penetration depths of the NTEs.
Trvalý link: http://hdl.handle.net/11104/0277935