Coronal implosion and particle acceleration in the wake of a filament eruption

Document Type

Article

Publication Date

1-1-2009

Abstract

We study the evolution of a group of TRACE 195 coronal loops overlying a reverse S-shaped filament on 2001 June 15. These loops were initially pushed upward with the filament ascending and kinking slowly, but as soon as the filament rose explosively, they began to contract at a speed of 100 km s -1, and sustained for at least 12 minutes, presumably due to the reduced magnetic pressure underneath with the filament escaping. Despite the contraction following the expansion, the loops of interest remained largely intact during the filament eruption, rather than formed via reconnection. These contracting loops naturally formed a shrinking trap, in which hot electrons of several keV, in an order of magnitude estimation, can be accelerated to nonthermal energies. A single hard X-ray (HXR) burst, with no corresponding rise in GOES soft X-ray (SXR) flux, was recorded by the Hard X-ray Telescope (HXT) on board Yohkoh, when the contracting loops expectedly approached the post-flare arcade originating from the filament eruption. HXT images reveal a coronal source distinctly above the top of the SXR arcade by 15″. The injecting electron population for the coronal source (thin target) is hardening by 1.5 powers relative to the footpoint emission (thick target), which is consistent with electron trapping in the weak diffusion limit. Although we cannot rule out additional reconnection, observational evidence suggests that the shrinking coronal trap may play a significant role in the observed nonthermal HXR emission during the flare decay phase. © 2009 The American Astronomical Society.

Identifier

77949521098 (Scopus)

Publication Title

Astrophysical Journal

External Full Text Location

https://doi.org/10.1088/0004-637X/703/1/L23

e-ISSN

15384357

ISSN

0004637X

First Page

L23

Last Page

L28

Issue

1 PART 2

Volume

703

Grant

0849453

Fund Ref

National Science Foundation

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