ROSAT HRI OBSERVATIONS OF THE LOCAL GROUP GALAXIES IC-10, NGC-147 ANDNGC-185

We report on pointed X-ray observations of IC 10, NGC 147 and NGC 185 made with the ROSAT High Resolution Imager (HRI). These are three Loca l Group galaxies that have never been previously studied in detail in the X-ray regime. IC 10 is the closest starburst galaxy to our own Gal axy, and NGC 147 and NGC 185 are companions to M31. We have discovered a variable X-ray source coincident with IC 10. The source is located near the centre of a large, non-thermal bubble of radio emission, and it is positionally coincident with an emission-line star in IC 10 whic h has been classified as a WN-type Wolf-Rayet star. We demonstrate tha t a confusing foreground or background source is improbable. The X-ray source is probably an X-ray binary in IC 10, and it may be a Wolf-Ray et + black hole binary. The source has mean and maximum 0.1-2.5 keV is otropic luminosities of about 2 and 4 x 10(38) erg s(-1), respectively . We do not detect any sources in the central regions of NGC 147 or NG C 185. We place upper limits on their central X-ray emission, and we l ist all X-ray sources coincident with their outer extents. We also pre sent the first X-ray detections of the well-studied Algol-type binary TV Gas and the W UMa-type binary BH Gas, which were both serendipitous ly observed during our IC 10 pointing.