Non-LTE Calculations of the Mg I 12.32 $\mu$m Line in a Flaring Atmosphere

Abstract

The infrared Mg I lines near 12 microns are a pair of emission lines which are magnetically sensitive and have been used to measure solar magnetic fields. Here we calculate the response of the Mg I 12.32 $\mu$m line during a flare and find that in our modeling this line has a complicated behavior. At the beginning of the flare heating, this line shows an intensity dimming at the line center. The intensity then increases when heating continues, with increasing contributions from the heated layers in the chromosphere. The line formation height and the line width also increase as a result. As for the polarized line profiles, we find that flare heating tends to decrease the Zeeman splitting width and attenuates the Stokes $V$ lobe intensity. The wider features in the Stokes $V$ profiles are more pronounced during flare heating, which should be considered when performing magnetic field inversions.

12 pages, 4 figures, accepted by ApJ

References in corpus (4)

• An Open Source, Massively Parallel Code for Non-LTE Synthesis and Inversion of Spectral Lines and Zeeman-induced Stokes Profiles
• RH 1.5D: a massively parallel code for multi-level radiative transfer with partial frequency redistribution and Zeeman polarisation
• RADYN simulations of non-thermal and thermal models of Ellerman bombs
• The Response of the Lyman-Alpha Line in Different Flare Heating Models

Cited by in corpus (1)

• Infrared diagnostics of the solar magnetic field with Mg I 12 $\mu$m lines: forward-model results