Quasi-Periodic Pulsations (QPPs) in Solar Micro Flares
From polarized spectroscopic observations at RATAN-600 on January 25, 2017, we detected a strong "micro flare" with QPPs; it was unnoticed by the global solar monitoring stations working in various ranges. A characteristic feature of the spectrum lies in the fact that the gradual increase of flux with wavelength was followed by an abrupt explosive brightening in the range of 3-4 GHz tens times greater than the brightness of the quiescent Sun. Studies of the time evolution and comparison with EUV (extreme UV) showed that this type-B2 micro flare was initiated by the appearance of an S-like loop. The polarized radio emission from this micro flare observed at RATAN-600 was generated by non-thermal electrons, whose hard X ray emission was detected with the RHESSI space mission. The result is unique, as the limiting parameters combined the space and ground-based observation complexes and a rare flash event with a new radiation mechanism was detected.
Authors: Nakariakov V.M. (SAO RAS, the University of Warwick, GB), Anfinogentov S. (ISTP SB RAS), Storozhenko A.A. (SAO RAS), Kurochkin E.A. (SAO RAS), Bogod V.M. (SAO RAS), Sharykin I.N. (OFMZ SB RAS, IKI RAS), Kaltman T.I. (SAO RAS).
1. Nakariakov, V.M., Anfinogentov, S., Storozhenko, A.A., Kurochkin, E.A., Bogod, V.M., Sharykin, I.N., Kaltman, T.I., Quasi-periodic pulsations in a solar microflare, Astrophys. J. 859, 154, 2018
2. V.M. Bogod, T.I. Kaltman, A.A. Pervakov, Yu.V. Sotnikova, S.A. Trushkin (SAO RAS, Russia) Solar powerful short-term flare in NOAA12628 at 3-4 GHz on 25 Jan 2017, 10:16:43 UT ATel #10011; on 27 Jan 2017; 13:32 UT .