ROSAT PSPC Observations of Two Low Luminosity Early-Type Galaxies
Abstract
The x-ray spectra of early-type galaxies are composites of discrete source and diffuse hot gas components. While the emission from the most luminous galaxies is dominated by hot gas, simple scaling and binding mass arguments predict that discrete sources should become important below some transition optical luminosity. If early-type galaxies have massive halos comprising 90% of their mass and the best observational estimate of the Type Ia supernova rate, this transition luminosity should be at L_B ~ 3\ 10(10}L_{sun ) . We present ROSAT PSPC observations of two early-type galaxies, NGC 3607 and NGC 4697, with luminosites near this transition. We discuss the spectral and spatial evidence for discrete source emission, and the resulting implications for the luminosity-scaling of the supernova rate and dark matter in early-type galaxies.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1993
- Bibcode:
- 1993AAS...183.4202L