Simulations of the Mg II k and Ca II 8542 lines from an Alfvén Wave-heated Flare Chromosphere
Abstract
We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfvén wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show that the distinctive atmospheric evolution in the mid-to-upper chromosphere results in Mg II k-line emission that should be observably different between wave-heated and beam-heated simulations. We also present Ca II 8542 Å profiles that are formed slightly deeper in the chromosphere. The Mg II k-line profiles from our wave-heated simulation are quite different from those from a beam-heated model and are more consistent with Interface Region Imaging Spectrograph observations. The predicted differences between the Ca II 8542 Å in the two models are small. We conclude that careful observational and theoretical study of lines formed in the mid-to-upper chromosphere holds genuine promise for distinguishing between competing models for chromospheric heating in flares.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2016
- DOI:
- 10.3847/0004-637X/827/2/101
- arXiv:
- arXiv:1605.05888
- Bibcode:
- 2016ApJ...827..101K
- Keywords:
-
- methods: numerical;
- Sun: atmosphere;
- Sun: chromosphere;
- Sun: flares;
- Sun: UV radiation;
- waves;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 17 pages, 9 figures, submitted for peer-review