2009/02/28 by J. Kašparová, J. Kasparova, M. Karlický +1 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Earthquake Detection and Analysis #Ionosphere and magnetosphere dynamics #Solar and Space Plasma Dynamics #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/200911898
published as Astron.Astrophys. 497 (2009) L13-L16 · 4 pages, 4 figures, changed content, accepted to A&A
arxiv created 2009/03/13 · openalex publication_date 2009/03/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
<i>Aims. <i/>We investigate whether the so-called kappa distribution, often used to fit electron distributions detected in situ in the solar wind, can describe electrons producing the hard X-ray emission in solar flares.<i>Methods. <i/>Using Ramaty High Energy Solar Spectroscopic imager (RHESSI) flare data we fit spatially- and feature-integrated spectra, assuming a kappa distribution for the mean electron flux spectrum.<i>Results. <i/>We show that a single kappa distribution generally cannot describe spatially integrated X-ray emission composed of both footpoint and coronal sources. In contrast, the kappa distribution is consistent with mean electron spectra producing hard X-ray emission in some coronal sources.