The coronal temperatures of low-mass main-sequence stars
- Author(s)
- Colin Johnstone, Manuel Güdel
- Abstract
Aims: We study the X-ray emission of low-mass main-sequence stars to derive a reliable general scaling law between coronal temperature and the level of X-ray activity.
Methods: We collect ROSAT measurements of hardness ratios and X-ray luminosities for a large sample of stars to derive which stellar X-ray emission parameter is most closely correlated with coronal temperature. We calculate average coronal temperatures for a sample of 24 low-mass main-sequence stars with measured emission measure distributions (EMDs) collected from the literature. These EMDs are based on high-resolution X-ray spectra measured by XMM-Newton and Chandra.
Results: We confirm that there is one universal scaling relation between coronal average temperature and surface X-ray flux, FX, that applies to all low-mass main-sequence stars. We find that coronal temperature is related to FX by T̅cor = 0.11 FX0.26, where T̅cor is in MK and FX is in erg s-1 cm-2.
- Organisation(s)
- Department of Astrophysics
- Journal
- Astronomy & Astrophysics
- Volume
- 578
- No. of pages
- 4
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/201425283
- Publication date
- 06-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/the-coronal-temperatures-of-lowmass-mainsequence-stars(946d2e39-378c-44e4-b1c0-1f8814fe99fe).html