The Cause of Photospheric and Helioseismic Responses to Solar Flares: High-Energy Electrons or Protons?

Abstract

Analysis of the hydrodynamic and helioseismic effects in the photosphere during the solar flare of July 23, 2002, observed by Michelson Doppler Imager (MDI) on SOHO, and high-energy images from RHESSI shows that these effects are closely associated with sources of the hard X-ray emission, and that there are no such effects in the centroid region of the flare gamma-ray emission. These results demonstrate that contrary to expectations the hydrodynamic and helioseismic responses (''sunquakes") are more likely to be caused by accelerated electrons than by high-energy protons. A series of multiple impulses of high-energy electrons forms a hydrodynamic source moving in the photosphere with a supersonic speed. The moving source plays a critical role in the formation of the anisotropic wave front of sunquakes.

13 pages, 5 figures, ApJL in press

References in corpus (1)

• On the origin of 3 seismic sources in the proton-rich flare of October 28, 2003

Cited by in corpus (8)

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• Energy Release and Initiation of Sunquake in C-class Flare
• Comparison of Emission Properties of two Homologous Flares in AR 11283
• Flare Induced Photospheric Velocity Diagnostics
• Highly Energetic Electrons Accelerated in Strong Solar Flares as a Preferred Driver of Sunquakes
• The 17 February 2013 sunquake in the context of the active region's magnetic field configuration
• Geometric properties of acoustic waves generated by a point source in solar-like interior: effects of acoustic cut-off frequency
• A Possible Selection Rule for Flares Causing Sunquakes