A soft X-ray observation of ω Centauri with EXOSAT.
van Paradijs, J.; Jansen, F.; Verbunt, F.; Arnaud, K. A.; Shafer, R. A.
Germany, Netherlands, United States
Abstract
In an observation with the LE1 CMA detector of the EXOSAT observatory the authors have detected two of the X-ray sources previously discovered in the globular cluster ω Cen with the IPC detector on board of the Einstein satellite. They give improved positions for these two sources. On the basis of comparison of the EXOSAT and Einstein count rates it is concluded that these two sources in ω Cen are either very soft (kT ≡ 40eV) or highly variable. If they are very soft, previous estimates of their X-ray luminosity can be too high by an order of magnitude.