X-ray Detection of the Cluster Containing the Cepheid S Mus
Abstract
The galactic Cepheid S Muscae has recently been added to the important list of Cepheids linked to open clusters, in this case the sparse young cluster ASCC 69. Low-mass members of a young cluster are expected to have rapid rotation and X-ray activity, making X-ray emission an excellent way to discriminate them from old field stars. We have made an XMM-Newton observation centered on S Mus and identified (Table 1) a population of X-ray sources whose near-IR 2MASS counterparts lie at locations in the J, (J-K) color-magnitude diagram consistent with cluster membership at the distance of S Mus. Their median energy and X-ray luminosity are consistent with young cluster members as distinct from field stars. These strengthen the association of S Mus with the young cluster, making it a potential Leavitt Law (Period-Luminosity relation) calibrator.
Keywords
Cite
@article{arxiv.1403.6939,
title = {X-ray Detection of the Cluster Containing the Cepheid S Mus},
author = {Nancy Remage Evans and Ignazio Pillitteri and Scott J. Wolk and Edward Guinan and Scott Engle and Howard E. Bond and Gail H. Schaefer and Margarita Karovska and Joseph DePasquale and Evan Tingle},
journal= {arXiv preprint arXiv:1403.6939},
year = {2015}
}
Comments
7 pages, 1 figure. Accepted for publication on ApJL