A Study on Red Asymmetry of H alpha Flare Ribbons Using a Narrowband Filtergram in the 2001 April 10 Solar Flare

作者：Asai Ayumi^*; Ichimoto Kiyoshi; Kitai Reizaburo; Kurokawa Hiroki; Shibata Kazunari

来源：Publications of the Astronomical Society of Japan, 2012, 64(1).

DOI：10.1093/pasj/64.1.20

• acceleration of particles
• Sun: chromosphere
• Sun: corona
• Sun: flares

We report on a detailed examination of the "red asymmetry" of the Ha emission line seen during the 2001 April 10 solar flare by using a narrowband filtergram. We investigated the temporal evolution and the spatial distribution of the red asymmetry by using Ha data taken with the 60-cm Domeless Solar Telescope at Hida Observatory, Kyoto University. We confirmed that the red asymmetry clearly appeared all over the flare ribbons, and the strong red asymmetry is located on the outer narrow edges of the flare ribbons, with a width of about 1 ''.1/5-3 ''.0 (1000-2000 km), where strong energy releases occur. Moreover, we found that the red asymmetry, which also gives a measure of the Doppler shift of the Ha emission line, concentrates on a certain value, not depending on the intensity of the Ha kernels. This implies not only that the temporal evolutions of the red asymmetry and those of the intensity are not synchronous in each flare kernel, but also that the peak asymmetry (or velocity of the chromospheric condensation) of individual kernel is not a strong function of their peak intensity.

• 出版日期2012-2-25