On Temperature and Abundance Effects During an X-Ray Flare on Sigma Geminorum

Abstract

We compare quiescent and flare X-ray spectra of the RS CVn binary Sigma Gem obtained with the Chandra and XMM-Newton grating spectrometers. We find that in addition to an overall 25% flux increase, which can be ascribed to variations in the system's quiescence activity over the 15 months that passed between the observations, there is a hot plasma component of kT_e > 3 keV that arises with the flare. The hot component is manifested primarily by emission from high charge states of Fe and by a vast continuum. The cooler (kT_e < 2 keV) plasma remains undisturbed during the flare. We find no significant variations in the relative abundances during the flare except for a slight decrease (<30%) of O and Ne.

6 pages, 4 figures, Accepted for publication in A&A

References in corpus (3)

• Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton
• A Study of the Coronal Plasma in RS CVn binary systems
• Detection of the Neupert Effect in the Corona of an RS CVn Binary System by XMM-Newton and the VLA

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• Six Large Coronal X-ray Flares Observed With Chandra
• XRISM view of a stellar flare: High-resolution Fe K spectra of HR 1099, an RS CVn-type star