ITAL]ROSAT[/ITAL] High Resolution Imager Identifications of Suspected Stellar Sources from the [ITAL]Einstein[/ITAL] Slew Survey

Abstract

We present analysis of a series of ROSAT High Resolution Imager (HRI) observations of 16 X-ray detections from the Einstein Slew Survey (ESS). The data were taken to resolve ambiguous ESS identifications based on optical spectroscopy. For 10 of the 16 detections, the previous identification has been confirmed—six with solar-type stars (spectral types F–K), one each with a cataclysmic variable, a B2 V, a dMe star, and one with a BL Lac object. For another detection, two potential counterparts are unresolvable even with the HRI. The HRI does resolve two other ESS detections into two distinct X-ray sources, but no HRI source is found for the remaining three X-ray detections. HRI-derived fluxes are consistent with those measured by the ROSAT All-Sky Survey for their 12 common detections, and improved positions are obtained for these sources. We calculate values of fX/fV and LX for these stars where possible and find values consistent with those expected for corresponding spectral types.