The Decay of Stellar Dynamos and X-ray Activity
Abstract
Existing stellar X-ray surveys suggest major problems in our understanding of the evolution of stellar magnetic activity in solar and late-type stars, reaching conflicting conclusions over the rate of decay of X-ray activity and the spectral types responsible. We are confronting these discrepancies with a new model of the expected stellar X-ray luminosity distribution, combining a Galactic population synthesis model with current theories for rotational spin- down and the rotation - activity relation for the stellar magnetic dynamo. Here we test our model using new observations of the stellar content of the Chandra COSMOS survey, for which 60 new stellar X-ray sources are identified from the thin disk and Galactic halo populations. Our model is in approximate agreement with the observed X-ray luminosity distribution and the distribution of spectral types responsible. However, slight differences in the form of the X-ray luminosity distribution exist that may hint at problems in our understanding of stellar X-ray emission.
Keywords
Cite
@article{arxiv.1012.0314,
title = {The Decay of Stellar Dynamos and X-ray Activity},
author = {Nicholas J. Wright and Jeremy J. Drake and Francesca Civano},
journal= {arXiv preprint arXiv:1012.0314},
year = {2019}
}
Comments
8 pages, 3 figures. To appear in the proceedings of Cool Stars 16: 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun