Astron. Astrophys. 337, 294-298 (1998)

A possible mechanism for the H broad wings emission of Ellerman bombs

J.-C. Hénoux ¹, C. Fang ^{1, 2} and M.D. Ding <sup>2

1</sup> Observatoire de Paris, DASOP, CNRS-URA 2080, Meudon, France
² Department of Astronomy, Nanjing University, Nanjing, P.R. China

Received 8 January 1998 / Accepted 19 May 1998

Abstract

In this paper, the non-thermal emission of Ly, Ly and H lines generated through charge exchange by protons accelerated in the low chromosphere and moving with a small pitch angle around an horizontal magnetic field has been computed. Computations have been done for observations made at the center of the solar disk, i.e. in a situation where the solar magnetic field is perpendicular to the line of sight, for non zero pitch angles. In such conditions, the photons emitted through charge exchange are Doppler shifted symmetrically in both wings of the lines. The H far line wing intensities increase significantly, making possible to reproduce the characteristics of the spectra of Ellerman bombs. Thus it is proposed that a proton beam accelerated in the low chromosphere, and losing its energy there, is a viable candidate for explaining the observed EB spectra.

Key words: line: profiles radiation mechanisms: non-thermal Sun: chromosphere

Send offprint requests to: J.-C. Hénoux

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Contents

• 1. Introduction
• 2. A possible mechanism for emission in the H far line wings
  • 2.1. Proton-hydrogen charge exchange
  • 2.2. Non-thermal emission
  • 2.3. Transfer of H radiation, net excess H emission
• 3. Discussion and conclusion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: August 6, 1998
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