Energy partitions and evolution in a purely thermal solar flare

Document Type

Article

Publication Date

4-1-2015

Abstract

This paper presents a solely thermal flare, which we detected in the microwave range from the thermal gyro- and free-free emission it produced. An advantage of analyzing thermal gyro emission is its unique ability to precisely yield the magnetic field in the radiating volume. When combin ed with observationally deduced plasma density and temperature, these magnetic field measurements offer a straightforward way of tracking evolution of the magnetic and thermal energies in the flare. For the event described here, the magnetic energy density in the radio-emitting volume declines over the flare rise phase, then stays roughly constant during the extended peak phase, but recovers to the original level over the decay phase. At the stage where the magnetic energy density decreases, the thermal energy density increases; however, this increase is insufficient, by roughly an order of magnitude, to compensate for the magnetic energy decrease. When the magnetic energy release is over, the source parameters come back to nearly their original values. We discuss possible scenarios to explain this behavior.

Identifier

84926476346 (Scopus)

Publication Title

Astrophysical Journal

External Full Text Location

https://doi.org/10.1088/0004-637X/802/2/122

e-ISSN

15384357

ISSN

0004637X

Issue

2

Volume

802

Grant

1312802

Fund Ref

National Science Foundation

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