The Low-Luminosity X-Ray Sources in Omega Centauri

Abstract

The authors report multicolor CCD photometry of the fields of three X-ray sources in ω Centauri; two have very accurate (10arcsec) EXOSAT X-ray positions, in addition to observations from the Einstein Observatory. The crowding in these X-ray fields is moderate and does not preclude accurate photometry of individual objects. Although the data in the best case reach to V = 24.5, corresponding to M_V= 10.6 in the cluster (and well beneath the expected quiescent luminosity of cataclysmic variables (CV), the authors find no evidence for any CV optical candidates.