Cosmic ray interactions in the solar atmosphere

Hudson, H. S. , MacKinnon, A. , Szydlarski, M. and Carlsson, M. (2020) Cosmic ray interactions in the solar atmosphere. Monthly Notices of the Royal Astronomical Society, 491(4), pp. 4852-4856. (doi: 10.1093/mnras/stz3373)

206940.pdf - Published Version



High-energy particles enter the solar atmosphere from Galactic or solar coronal sources, and produce ‘albedo’ emission from the quiet Sun that is now observable across a wide range of photon energies. The interaction of high-energy particles in a stellar atmosphere depends essentially upon the joint variation of the magnetic field and plasma density, which heretofore has been characterized parametrically as P ∝ Bα with P the gas pressure and B the magnitude of the magnetic field. We re-examine that parametrization by using a self-consistent 3D MHD model (Bifrost) and show that this relationship tends to P ∝ B3.5 ± 0.1 based on the visible portions of the sample of open-field flux tubes in such a model, but with large variations from point to point. This scatter corresponds to the strong meandering of the open-field flux tubes in the lower atmosphere, which will have a strong effect on the prediction of the emission anisotropy (limb brightening). The simulations show that much of the open flux in coronal holes originates in weak-field regions within the granular pattern of the convective motions seen in the simulations.

Item Type:Articles
Glasgow Author(s) Enlighten ID:MacKinnon, Dr Alexander and Hudson, Dr Hugh
Authors: Hudson, H. S., MacKinnon, A., Szydlarski, M., and Carlsson, M.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Monthly Notices of the Royal Astronomical Society
Publisher:Oxford University Press
ISSN (Online):1365-2966
Published Online:17 December 2019
Copyright Holders:Copyright © 2019 The Authors
First Published:First published in Monthly Notices of the Royal Astronomical Society 491(4): 4852-4856
Publisher Policy:Reproduced in accordance with the publisher copyright policy
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