Issue |
A&A
Volume 686, June 2024
|
|
---|---|---|
Article Number | A291 | |
Number of page(s) | 9 | |
Section | The Sun and the Heliosphere | |
DOI | https://doi.org/10.1051/0004-6361/202348589 | |
Published online | 20 June 2024 |
Solar prominence diagnostics and their associated estimated errors from 1D NLTE Mg II h&k modelling
1
University of Wrocław, Centre of Scientific Excellence – Solar and Stellar Activity, Kopernika 11, 51-622 Wrocław, Poland
e-mail: aaron.peat@uwr.edu.pl
2
SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
3
ETH-Zurich, Hönggerberg Campus, HIT Building, Zürich, Switzerland
4
PMOD/WRC, Dorfstrasse 33, 7260 Davos Dorf, Switzerland
5
LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, 5 Place Jules Janssen, 92190 Meudon, France
6
KU-Leuven, 3001 Leuven, Belgium
Received:
13
November
2023
Accepted:
17
April
2024
Aims. We present further development of the rolling root mean square (rRMS) algorithm. These improvements consist of an increase in computational speed and an estimation of the uncertainty on the recovered diagnostics. This improved algorithm is named the cross root mean square (xRMS) algorithm.
Methods. We used the quantile method to recover the statistics of the line profiles in order to study the evolution of the prominence observed by IRIS on 1 October 2019. We then introduced the improvements to rRMS. These improvements greatly increased the computational speed, and this increase in speed allowed us to use a large model grid. Thus, we utilised a grid of 23 940 models to recover the thermodynamic diagnostics. We used the “good” (but not “best”) fitting models to recover an estimate of the uncertainty on the recovered diagnostics.
Results. The maximum line-of-sight (LOS) velocities were found to be 70 km s−1. The line widths were mostly 0.4 Å, with the asymmetries of most pixels around zero. The central temperature of the prominence was found to range from 10 kK to 20 kK, with uncertainties of approximately ±5 to ±15 kK. The central pressure was around 0.2 dyn cm−2, with uncertainties of ±0.2 to ±0.3 dyn cm−2. The ionisation degree ranged from 1 to 1000, with uncertainties mostly in the range ±10 to ±100. The electron density was mostly 1010 cm−3, with uncertainties of mostly ±109.
Conclusions. The new xRMS algorithm finds an estimation of the errors of the recovered thermodynamic properties. To our knowledge, this is the first attempt at systematically determining the errors from forward modelling. The large range of errors found may hint at the degeneracies present when using a single ion and/or species from forward modelling. In the future, co-aligned observations of more than one ion and/or species should be used to attempt to constrain this problem.
Key words: Sun: chromosphere / Sun: filaments / prominences / Sun: UV radiation
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.