Detection of Acceleration Processes During the Initial Phase of the 12 June 2010 Flare

• Published in: Solar physics Vol. 280; no. 2; pp. 525 - 535
• Main Authors: Kashapova, L. K., Meshalkina, N. S., Kisil, M. S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2012; Springer Nature B.V
• Subjects: Advances in European Solar Physics; Astrophysics and Astroparticles; Atmospheric Sciences; Emissions; Gamma rays; Physics; Physics and Astronomy; Solar flares; Solar physics; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Russia, Siberia; Heating, in flares; X-ray bursts, association with flares; Radio bursts, association with flares; Energetic particles; Flares
• ISSN: 0038-0938; 1573-093X
• DOI: 10.1007/s11207-012-0080-z

We present an analysis of the plasma parameters during the initial phase of the 12 June 2010 flare (SOL2010-06-12T00:57). A peculiarity of the flare was the detection of
γ
-ray emission that is unusual for such weak and short event. The analysis revealed the presence of a flare precursor detected about five minutes before the flare onset in 94 Å images which spatially coincided with the non-polarized microwave (MW) source at 17 GHz (the
Nobeyama Radio Heliograph
) that is the Neutral Line associated Source (NLS). A comparison of the results obtained from MW data by the
Nobeyama Radio Polarimeters
and the multi-frequency
Siberian Radioheliograph
(the new 10-antenna radio heliograph prototype at 4.6 and 6.4 GHz) and hard X-ray (HXR) observations by the
Fermi Gamma-ray Space Telescope
reveal the presence of accelerated electrons during the flare’s initial phase. The analysis of MW and HXR spectra also confirms the presence of accelerated particles. Moreover, a good temporal correlation between several light curves in different HXR energy bands and at MW frequencies indicates the generation of both HXR and MW emission by a common population of accelerated electrons. Detection of accelerated particles during the initial phase of the flare and soft-hard-harder (SHH) behavior of the spectra indicate several episodes of particle acceleration and confirm the non-impulsive type of the flare evolution.