CAOSP abstracts, Volume: 41, No.: 2, year: 2011

Abstract: We present here results of simultaneous observations of hard X-ray radiation (HXR) sources and Hα brightenings recorded during the impulsive phase of a solar flare. Using high cadence observations we analyzed relationships of localizations as well as intensity variations of the sources observed in both wavelength domains. The visible data taken in the Hα line (2D spectra-images) were collected with the Multi-Channel Subtractive Double Pass spectrograph and Solar Eclipse Coronal Imaging System at the Białków Observatory (the University of Wrocław, Poland) with high time resolution (up to 40 ms). The HXR images were reconstructed using Reuven Ramaty High Energy Solar Spectroscopic Imager observations. We found good spatial agreement between HXR non-thermal and Hα thermal emission sources, confirming our earlier results showing a very fast radiative response of the solar chromosphere in Hα to energy deposited by non-thermal electrons during the impulsive phase of solar flares.