Description
We present the results of a Chandra ACIS-I survey of a high-latitude region at 13h +38{deg} which was earlier observed with ROSAT and which has recently been observed by XMM-Newton for 200ks. XMM-Newton will provide good-quality X-ray spectra for over 200 sources with fluxes around the knee of the logN/logS, which are responsible for the bulk of the X-ray background. The main aim of the Chandra observations is to provide arcsecond, or better, positions, and hence reliable identifications, for the XMM-Newton sources. The ACIS-I observations were arranged in a mosaic of four 30-ks pointings, covering almost all of the 15-arcmin radius XMM-Newton/ROSAT field. We detect 214 Chandra sources above a Cash likelihood statistic of 25, which approximates to 5{sigma} significance, to a limiting flux of ~1.3x10^-15^erg/cm^2^/s (0.5-7keV). Optical counterparts are derived from a Subaru SuprimeCam image reaching to R~27. The very large majority of the Chandra sources have an optical counterpart, with the distribution peaking at 23<R<24, although 14 have no counterpart to R=27. The fraction of X-ray sources with no identification brighter than R=27 is similar to that found in deeper Chandra surveys.
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