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X-ray sources and their optical counterparts in the globular cluster M 22

N. A. Webb·D. Serre·B. Gendre·D. Barret·J. -P. Lasota·L. Rizzi
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Abstract

Using XMM-Newton EPIC imaging data, we have detected 50 low-luminosity X-ray sources in the field of view of M 22, where 5 +/- 3 of these sources are likely to be related to the cluster. Using differential optical photometry, we have identified probable counterparts to those sources belonging to the cluster. Using X-ray spectroscopic and timing studies, supported by the optical colours, we propose that the most central X-ray sources in the cluster are cataclysmic variables, millisecond pulsars, active binaries and a blue straggler. We also identify a cluster of galaxies behind this globular cluster.

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N. A. Webb, D. Serre, B. Gendre, D. Barret, J. -P. Lasota, L. Rizzi. 2004-05-28. X-ray sources and their optical counterparts in the globular cluster M 22. https://doi.org/10.1051/0004-6361%3A20040399

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