TY - JOUR
T1 - Radio and X-Ray Observations of Short-lived Episodes of Electron Acceleration in a Solar Microflare
AU - Sharma, Rohit
AU - Battaglia, Marina
AU - Luo, Yingjie
AU - Chen, Bin
AU - Yu, Sijie
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved..
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Solar flares are sudden energy release events in the solar corona, resulting from magnetic reconnection, that accelerate particles and heat the ambient plasma. During a flare, there are often multiple temporally and spatially separated individual energy release episodes that can be difficult to resolve depending on the observing instrument. We present multiwavelength imaging and spectroscopy observations of multiple electron acceleration episodes during a GOES B1.7-class two-ribbon flare on 2012 February 25, observed simultaneously with the Karl G. Jansky Very Large Array at 1-2 GHz, the Reuven Ramatay High Energy Solar Spectroscopic Imager in X-rays, and the Solar Dynamics Observatory in extreme ultraviolet. During the initial phase of the flare, five radio bursts were observed. A nonthermal X-ray source was seen to be cotemporal but not cospatial with the first three radio bursts. Their radio spectra are interpreted as optically thick gyrosynchrotron emission. By fitting the radio spectra with a gyrosynchrotron model, we derive the magnetic field strength and nonthermal electron spectral parameters in each acceleration episode. Notably, the nonthermal parameters derived from X-rays differ considerably from the nonthermal parameters inferred from the radio. The observations are indicative of multiple cotemporal acceleration episodes during the impulsive phase of a solar microflare. The X-ray and radio burst sources likely originate from separate electron distributions in different magnetic loops.
AB - Solar flares are sudden energy release events in the solar corona, resulting from magnetic reconnection, that accelerate particles and heat the ambient plasma. During a flare, there are often multiple temporally and spatially separated individual energy release episodes that can be difficult to resolve depending on the observing instrument. We present multiwavelength imaging and spectroscopy observations of multiple electron acceleration episodes during a GOES B1.7-class two-ribbon flare on 2012 February 25, observed simultaneously with the Karl G. Jansky Very Large Array at 1-2 GHz, the Reuven Ramatay High Energy Solar Spectroscopic Imager in X-rays, and the Solar Dynamics Observatory in extreme ultraviolet. During the initial phase of the flare, five radio bursts were observed. A nonthermal X-ray source was seen to be cotemporal but not cospatial with the first three radio bursts. Their radio spectra are interpreted as optically thick gyrosynchrotron emission. By fitting the radio spectra with a gyrosynchrotron model, we derive the magnetic field strength and nonthermal electron spectral parameters in each acceleration episode. Notably, the nonthermal parameters derived from X-rays differ considerably from the nonthermal parameters inferred from the radio. The observations are indicative of multiple cotemporal acceleration episodes during the impulsive phase of a solar microflare. The X-ray and radio burst sources likely originate from separate electron distributions in different magnetic loops.
KW - Solar energetic particles (1491)
KW - Solar flares (1496)
KW - Solar radio emission (1522)
KW - Solar radio flares (1342)
KW - The Sun (1693)
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U2 - 10.3847/1538-4357/abbd96
DO - 10.3847/1538-4357/abbd96
M3 - Article
AN - SCOPUS:85097455379
SN - 0004-637X
VL - 904
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 94
ER -