EDP Sciences
Free access
Volume 369, Number 3, April III 2001
Page(s) 1104 - 1111
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20010200

A&A 369, 1104-1111 (2001)
DOI: 10.1051/0004-6361:20010200

Drifting radio bursts and fine structures in the 0.8-7.6 GHz frequency range observed in the NOAA 9077 AR (July 10-14, 2000) solar flares

M. Karlický1, Y. Yan2, Q. Fu2, S. Wang2, K. Jiricka1, H. Mészárosová1 and Y. Liu2

1  Astronomical Institute of the Academy of Sciences of the Czech Republic, 25165 Ondrejov, Czech Republic
2  Beijing Astronomical Observatory/National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, PR China

(Received 10 November 2000 / Accepted 24 January 2001)

The 0.8-7.6 GHz global and detailed radio spectra of the four most intense flares observed in the NOAA 9077 active region (July 10-14, 2000) are presented. The radio bursts of these flares and their sequence reveal features indicative of topological similarities among the flares under study. The drifting pulsation structures were found to be the typical signatures of these flares. Furthermore, many other fine structures such as narrowband drifting lines, drifting harmonic structure with zebra patterns, drifting branches of narrowband dm-spikes, and structures with fast positively and negatively drifting bursts are shown in the context of the whole radio flares. Some of them were observed for the first time. The relationships among them and the resulting interpretations are summarized. The characteristic periods of the drifting pulsation structures and the magnetic field in the zebra radio source are determined.

Key words: Sun: activity -- Sun: flares -- Sun: radio radiation

Offprint request: M. Karlický, karlicky@asu.cas.cz

© ESO 2001