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Title: Time Variations of Observed H α Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare

Abstract

We compare time variations of the H α 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 H α 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 H α 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 H α emission of the flaring kernels can be explained by momentary changes of the deposited energy fluxmore » and the variations of the penetration depths of the NTEs.« less

Authors:
; ; ;  [1]
  1. Astronomical Institute, University of Wrocław, 51-622 Wrocław, ul. Kopernika 11 (Poland)
Publication Date:
OSTI Identifier:
22679810
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 847; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALPHA SPECTRA; BALMER LINES; CHROMOSPHERE; ELECTRONS; EMISSION; ENERGY ABSORPTION; ENERGY LOSSES; GAMMA RADIATION; HYDRODYNAMIC MODEL; LAYERS; PENETRATION DEPTH; PLASMA; PRECIPITATION; SOLAR FLARES; SUN; THERMODYNAMICS; TIME RESOLUTION; VISIBLE RADIATION; X RADIATION

Citation Formats

Falewicz, Robert, Radziszewski, Krzysztof, Rudawy, Paweł, and Berlicki, Arkadiusz, E-mail: falewicz@astro.uni.wroc.pl, E-mail: radziszewski@astro.uni.wroc.pl, E-mail: rudawy@astro.uni.wroc.pl, E-mail: berlicki@astro.uni.wroc.pl. Time Variations of Observed H α Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA89E9.
Falewicz, Robert, Radziszewski, Krzysztof, Rudawy, Paweł, & Berlicki, Arkadiusz, E-mail: falewicz@astro.uni.wroc.pl, E-mail: radziszewski@astro.uni.wroc.pl, E-mail: rudawy@astro.uni.wroc.pl, E-mail: berlicki@astro.uni.wroc.pl. Time Variations of Observed H α Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare. United States. doi:10.3847/1538-4357/AA89E9.
Falewicz, Robert, Radziszewski, Krzysztof, Rudawy, Paweł, and Berlicki, Arkadiusz, E-mail: falewicz@astro.uni.wroc.pl, E-mail: radziszewski@astro.uni.wroc.pl, E-mail: rudawy@astro.uni.wroc.pl, E-mail: berlicki@astro.uni.wroc.pl. Sun . "Time Variations of Observed H α Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare". United States. doi:10.3847/1538-4357/AA89E9.
@article{osti_22679810,
title = {Time Variations of Observed H α Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare},
author = {Falewicz, Robert and Radziszewski, Krzysztof and Rudawy, Paweł and Berlicki, Arkadiusz, E-mail: falewicz@astro.uni.wroc.pl, E-mail: radziszewski@astro.uni.wroc.pl, E-mail: rudawy@astro.uni.wroc.pl, E-mail: berlicki@astro.uni.wroc.pl},
abstractNote = {We compare time variations of the H α 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 H α 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 H α 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 H α 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.},
doi = {10.3847/1538-4357/AA89E9},
journal = {Astrophysical Journal},
number = 2,
volume = 847,
place = {United States},
year = {Sun Oct 01 00:00:00 EDT 2017},
month = {Sun Oct 01 00:00:00 EDT 2017}
}