A catalogue and analysis of X-ray luminosities of early-type galaxies
Abstract
We present a catalogue of X-ray luminosities for 401 early-type galaxies, of which 136 are based on newly analysed ROSAT PSPC pointed observations. The remaining luminosities are taken from the literature and converted to a common energy band, spectral model and distance scale. Using this sample we fit the LX:LB relation for early-type galaxies and find a best-fit slope for the catalogue of ~2.2. We demonstrate the influence of group-dominant galaxies on the fit and present evidence that the relation is not well modelled by a single power-law fit. We also derive estimates of the contribution to galaxy X-ray luminosities from discrete-sources and conclude that they provide Ldscr/LB~=29.5ergs-1LBsolar-1. We compare this result with luminosities from our catalogue. Lastly, we examine the influence of environment on galaxy X-ray luminosity and on the form of the LX:LB relation. We conclude that although environment undoubtedly affects the X-ray properties of individual galaxies, particularly those in the centres of groups and clusters, it does not change the nature of whole populations.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 2001
- DOI:
- 10.1046/j.1365-8711.2001.04890.x
- arXiv:
- arXiv:astro-ph/0108181
- Bibcode:
- 2001MNRAS.328..461O
- Keywords:
-
- CATALOGUES;
- SURVEYS;
- GALAXIES: ELLIPTICAL AND LENTICULAR;
- CD;
- X-RAYS: GALAXIES;
- Astrophysics
- E-Print:
- 33 pages, 16 postscript figures, accepted for publication in MNRAS