X-Ray Observations of Spiral Galaxies. II. Images and Spectral Parameters of 13 Galaxies
Abstract
The results of a spatial and spectral analysis of a sample of spiral galaxies observed in X-rays with the Einstein satellite indicate that the X-ray emission is generally extended and complex. In some cases, discrete, very bright X-ray sources are detected, some of these coincident with the nuclear regions. The spectral fit of the IPC data to a thermal bremsstrahlung spectrum with a low-energy absorption cutoff shows that the average spectrum could be rather hard with kT greater than 2 keV, and with low-energy cutoff consistent with line-of-sight absorption. Results on NGC 4631, NGC 6946, and the nuclei of IC 342 and NGC 1313 are discussed and compared with previous observations in different energy ranges.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1987
- DOI:
- 10.1086/165113
- Bibcode:
- 1987ApJ...315...46F
- Keywords:
-
- Astronomical Spectroscopy;
- Spiral Galaxies;
- X Ray Astronomy;
- Galactic Nuclei;
- Galactic Radiation;
- Spatial Distribution;
- Spectrum Analysis;
- X Ray Spectra;
- Astrophysics;
- GALAXIES: X-RAYS;
- X-RAYS: SPECTRA