We present evidence, based on Chandra ACIS-S observations of the nearby spiral galaxy NGC 6946, that the extraordinary X-ray luminosity of the MF 16 supernova remnant actually arises in a black hole X-ray binary. This conclusion is drawn from the point-like nature of the X-ray source, its X-ray spectrum closely resembling the spectrum of other ultraluminous X-ray sources thought to be black hole X-ray binary systems, and the detection of rapid hard X-ray variability from the source. We briefly discuss the nature of the hard X-ray variability, and the origin of the extreme radio and optical luminosity of MF 16 in light of this identification.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2003
- supernova remnants;
- galaxies: individual: NGC 6946;
- X-rays: binaries;
- 6 pages, 2 figures, accepted for publication in MNRAS