High-Resolution X-Ray Imaging of M33
Abstract
The nearby spiral galaxy M33 was observed for 35 ks with the high- resolution imager on ROSAT in 1992 January and August. We find 27 X-ray sources more luminous than 6 x 10^36^ ergs s^-1^ within 17.5' of the nucleus, of which 12 were discovered by the Einstein Observatory. Three of the ROSAT sources are coincident with giant H II regions, and seven are coincident or nearly coincident with supernova remnants. There is evidence for long-term variability between the Einstein and ROSAT observations in three sources, one of which was not detected in the ROSAT observations. Aside from an eclipsing binary X-ray source discovered by the Einstein Observatory, there is no evidence for variability within the ROSAT observations. Of the 120 cataloged holes in the H I layer in the field of view, two have significant X-ray emission. One is coincident with the giant H II region IC 133 while the other appears to be due to the chance superposition of a strong X-ray point source. Such holes are thought to be created by energetic stellar winds and supernovae from massive stars in young associations. We detect diffuse X-ray emission with a luminosity of about 10^39^ ergs s^-1^ which may trace the spiral arms within 10' of the nucleus.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1995
- DOI:
- 10.1086/175383
- Bibcode:
- 1995ApJ...441..568S
- Keywords:
-
- H Ii Regions;
- Interstellar Matter;
- Spiral Galaxies;
- Supernova Remnants;
- X Ray Astronomy;
- X Ray Imagery;
- X Ray Sources;
- Data Reduction;
- Heao 2;
- Rosat Mission;
- Stellar Luminosity;
- Stellar Winds;
- Supernovae;
- Astronomy;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M33;
- GALAXIES: ISM;
- ISM: H II REGIONS;
- ISM: SUPERNOVA REMNANTS;
- SURVEYS;
- X-RAYS: GALAXIES