Beam electrons as a source of Hα flare ribbons

Druett, Malcolm; Scullion, Eamon; Zharkova, Valentina; Matthews, Sarah; Zharkov, Sergei; Rouppe Van der Voort, Luc

Abstract

The observations of solar flare onsets show rapid increase of hard and soft X-rays, ultra-violet emission with large Doppler blue shifts associated with plasma upflows, and Hα hydrogen emission with red shifts up to 1–4 Å. Modern radiative hydrodynamic models account well for blue-shifted emission, but struggle to reproduce closely the red-shifted Hα lines. Here we present a joint hydrodynamic and radiative model showing that during the first seconds of beam injection the effects caused by beam electrons can reproduce Hα line profiles with large red-shifts closely matching those observed in a C1.5 flare by the Swedish Solar Telescope. The model also accounts closely for timing and magnitude of upward motion to the corona observed 29 s after the event onset in 171 Å by the Atmospheric Imaging Assembly/Solar Dynamics Observatory.

Citation

Druett, M., Scullion, E., Zharkova, V., Matthews, S., Zharkov, S., & Rouppe Van der Voort, L. (2017). Beam electrons as a source of Hα flare ribbons. Nature communications, 8, 13. https://doi.org/10.1038/ncomms15905

• Journal Article Type: Article
• Acceptance Date: May 12, 2017
• Online Publication Date: Jun 27, 2017
• Publication Date: Jun 27, 2017
• Deposit Date: Mar 8, 2018
• Publicly Available Date: Mar 9, 2018
• Journal: Nature Communications
• Electronic ISSN: 2041-1723
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Article Number: 15905
• Pages: 13
• DOI: https://doi.org/10.1038/ncomms15905
• Keywords: General biochemistry; Genetics and molecular biology; General physics and astronomy; General chemistry
• Public URL: https://hull-repository.worktribe.com/output/724344
• Publisher URL: https://www.nature.com/articles/ncomms15905
• Contract Date: Mar 8, 2018