TY - JOUR

T1 - Millimeter and X-Ray Emission from the 5 July 2012 Solar Flare

AU - Tsap, Y. T.

AU - Smirnova, V. V.

AU - Motorina, G. G.

AU - Morgachev, A. S.

AU - Kuznetsov, S. A.

AU - Nagnibeda, V. G.

AU - Ryzhov, V. S.

PY - 2018/3/1

Y1 - 2018/3/1

N2 - The 5 July 2012 solar flare SOL2012-07-05T11:44 (11:39 – 11:49 UT) with an increasing millimeter spectrum between 93 and 140 GHz is considered. We use space and ground-based observations in X-ray, extreme ultraviolet, microwave, and millimeter wave ranges obtained with the Reuven Ramaty High-Energy Solar Spectroscopic Imager, Solar Dynamics Observatory (SDO), Geostationary Operational Environmental Satellite, Radio Solar Telescope Network, and Bauman Moscow State Technical University millimeter radio telescope RT-7.5. The main parameters of thermal and accelerated electrons were determined through X-ray spectral fitting assuming the homogeneous thermal source and thick-target model. From the data of the Atmospheric Imaging Assembly/SDO and differential-emission-measure calculations it is shown that the thermal coronal plasma gives a negligible contribution to the millimeter flare emission. Model calculations suggest that the observed increase of millimeter spectral flux with frequency is determined by gyrosynchrotron emission of high-energy (≳ 300 keV) electrons in the chromosphere. The consequences of the results are discussed in the light of the flare-energy-release mechanisms.

AB - The 5 July 2012 solar flare SOL2012-07-05T11:44 (11:39 – 11:49 UT) with an increasing millimeter spectrum between 93 and 140 GHz is considered. We use space and ground-based observations in X-ray, extreme ultraviolet, microwave, and millimeter wave ranges obtained with the Reuven Ramaty High-Energy Solar Spectroscopic Imager, Solar Dynamics Observatory (SDO), Geostationary Operational Environmental Satellite, Radio Solar Telescope Network, and Bauman Moscow State Technical University millimeter radio telescope RT-7.5. The main parameters of thermal and accelerated electrons were determined through X-ray spectral fitting assuming the homogeneous thermal source and thick-target model. From the data of the Atmospheric Imaging Assembly/SDO and differential-emission-measure calculations it is shown that the thermal coronal plasma gives a negligible contribution to the millimeter flare emission. Model calculations suggest that the observed increase of millimeter spectral flux with frequency is determined by gyrosynchrotron emission of high-energy (≳ 300 keV) electrons in the chromosphere. The consequences of the results are discussed in the light of the flare-energy-release mechanisms.

KW - Flares, energetic particles

KW - Radio bursts, association with flares

KW - X-ray bursts

UR - http://www.scopus.com/inward/record.url?scp=85043231397&partnerID=8YFLogxK

U2 - 10.1007/s11207-018-1269-6

DO - 10.1007/s11207-018-1269-6

M3 - Article

AN - SCOPUS:85043231397

VL - 293

JO - Solar Physics

JF - Solar Physics

SN - 0038-0938

IS - 3

M1 - 50

ER -