Sources of Quasi-periodic Pulses in the Flare of 18 August 2012

0458324 - ASÚ 2017 RIV NL eng J - Journal Article
Altyntsev, A. - Meshalkina, N. - Mészárosová, Hana - Karlický, Marian - Palshin, V. - Lesovoi, S.
Sources of Quasi-periodic Pulses in the Flare of 18 August 2012.
Solar Physics. Roč. 291, č. 2 (2016), s. 445-463. ISSN 0038-0938. E-ISSN 1573-093X
R&D Projects: GA ČR GAP209/12/0103
Institutional support: RVO:67985815
Keywords : radio emission * active regions * oscillations
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 2.682, year: 2016

We analyzed spatial and spectral characteristics of quasi-periodic pulses for the limb flare on 18 August 2012, using new data from a complex of spectral and imaging instruments developed by the Siberian Solar Radio Telescope team and the Wind/Konus gamma-ray spectrometer. A sequence of broadband pulses with periods of approximately ten seconds were observed in X-rays at energies between 25 keV and 300 keV, and in microwaves at frequencies from a few GHz up to 34 GHz during an interval of one minute. The 17 and 34 GHz microwave sources were at the footpoints of the small loop system, the source emitting in the 4.2 – 7.4 GHz band in the large system. The QPPs were probably generated by modulated acceleration processes in the energy-release site. We determined the plasma parameters in the radio sources by analyzing the spectra. The microwave pulses might be explained by relatively weak variations of the spectral hardness of the emitting electrons.
Permanent Link: http://hdl.handle.net/11104/0259823