Observations of Thomson scattering from a loop-prominence system

Martínez Oliveros, J. C., Guevara Gómez, J. C., Saint-Hilaire, P., Hudson, H. and Krucker, S. (2022) Observations of Thomson scattering from a loop-prominence system. Astrophysical Journal, 936(1), p. 56. (doi: 10.3847/1538-4357/ac83b7)

Abstract

We describe observations of the white-light structures in the low corona following the X8.2 flare SOL 2017-09-10, as observed in full Stokes parameters by the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory. These data show both bright loops and a diffuse emission region above them. We interpret the loops as the white-light counterpart of a classical loop-prominence system, intermediate between the hot X-ray loops and coronal rain. The diffuse emission external to the loops is linearly polarized and has a natural interpretation in terms of Thomson scattering from the hot plasma seen prior to its cooling and recombination. The polarimetric data from HMI enable us to distinguish this contribution of scattering from the HMI pseudocontinuum measurement, and to make a direct estimation of the coronal mass in the polarized source. For a snapshot at 16:19 UT, we estimate a mass 8 × 1014 g. We further conclude that the volumetric filling factor of this source is near unity.

• Item Type: Articles
• Additional Information: J.C.G.G. wishes to acknowledge the SolarALMA project, which has received funding from the European Research Council (ERC) under the European Unionʼs Horizon 2020 research and innovation program (grant agreement No. 682462), and by the Research Council of Norway through its Centres of Excellence scheme, project No. 262622.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hudson, Dr Hugh
• Authors: Martínez Oliveros, J. C., Guevara Gómez, J. C., Saint-Hilaire, P., Hudson, H., and Krucker, S.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Astrophysical Journal
• Publisher: IOP Publishing
• ISSN: 0004-637X
• ISSN (Online): 1538-4357
• Published Online: 30 August 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Astrophysical Journal 936(1):56
• Publisher Policy: Reproduced under a Creative Commons license