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arXiv · 1403.6939

X-ray Detection of the Cluster Containing the Cepheid S Mus

Nancy Remage Evans·Ignazio Pillitteri·Scott J. Wolk·Edward Guinan·Scott Engle·Howard E. Bond·Gail H. Schaefer·Margarita Karovska·Joseph DePasquale·Evan Tingle
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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.

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Nancy Remage Evans, Ignazio Pillitteri, Scott J. Wolk, Edward Guinan, Scott Engle, Howard E. Bond, Gail H. Schaefer, Margarita Karovska, Joseph DePasquale, Evan Tingle. 2014-03-27. X-ray Detection of the Cluster Containing the Cepheid S Mus. https://doi.org/10.1088/2041-8205%2F785%2F2%2Fl25

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