X-ray, Hα, and radio observations of the two-ribbon flare of 16 May, 1981

• Published in: Solar physics Vol. 89; no. 2; pp. 355 - 378
• Main Authors: FARNIK, F, KAASTRA, J, KALMAN, B, KARLICKÝ, M, SLOTTJE, C, VALNICEK, B
• Format: Journal Article
• Language: English
• Published: Boston, MA Reidel 01.12.1983; Dordrecht
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; Flares, bursts, and related phenomena; Solar physics; Solar system; X ray observation; Hα line; Models; Radio observation; Spectroscopical observation; Solar flare
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/BF00217256

This paper is a contribution to the study of two-ribbon flares. A variety of observational material, i.e., H alpha pictures, radio spectrum in the frequency band 150-1000 MHz, radio map at 6 cm, fluxes at other frequencies, magnetograms, and X-ray flux in a broad energy interval, made it possible to study the development of the May 16, 1981, flare. The onset of the flare could be described by the model of Van Tend and Kuperus. A diminishing of the magnetic shear during the activation of the filament was observed. From radio and X-ray data, it was found that pulsed acceleration occurred in the region under the rising filament, with the electrons propagating in a limited region both upward to greater heights and downward into the footpoints. Internal oscillations of the filament were observed. A manifestation of the primary process of interplanetary shock-wave generation was found. The 6-cm radio sources could be localized in the footpoints of magnetic loops.