Колебания в активных областях Солнца на предвспышечной стадии

С. 7–10.

Абрамов-Максимов В. Е., Бакунина И.А.

We present a study of quasi-periodic oscillations (QPOs) of microwave emission from
some solar active regions (ARs) on pre-flare phase. We used the Nobeyama Radioheliograph
(NoRH) daily observations. The radio maps of the whole solar disk were synthesized in nonstandard
mode with a cadence of ten seconds and ten seconds averaging. We computed the
time series of maximum brightness temperature and total flux over selected field-of-view
(FOV) and used spectral wavelet analysis of the time series. We found that in most of the cases
an increase in the power of QPOs before flares is observed. The periods of oscillation are
different and vary from 3 to 100 minutes. The duration of pre-flare wavetrains in periods of
oscillations is approximately the same for all cases and is about 5 pulses. The effect of the
occurrence of the QPOs before flares can be interpreted as a relationship between MHD
waves propagating along the magnetic flux tube of sunspot and beginning of the flares and
can be considered as a flare precursor.

Keywords: микроволновое излучение, солнечные вспышки, solar flares, microwave emission, quasiperiodic oscillations, квазипериодические колебания

In book

Труды XXIII Всероссийской ежегодной конференции по физике Солнца “Солнечная и солнечно-земная физика - 2019”, 7-11 октября 2019, ГАО РАН

Главная (Пулковская) астрономическая обсерватория РАН, 2019.