Hard power-law emission components in the X-ray spectra of elliptical galaxies
Abstract
We report the first detections of hard power-law emission components in the X-ray spectra of six giant elliptical galaxies with previously-reported evidence for supermassive black holes in their nuclei. The observations were carried out with the ASCA satellite.The mean photon index, Gamma =1.2, and luminosities of the detected power-law components (L_{X,1-10} ~ 2.6 x 10(40) -2.1 x 10(42) ergs(-1) ) suggest that the emission originates in the accretion process around the central black holes and is most plausibly due to low-radiative efficiency accretion. Detailed models and important implications of this discovery are discussed.
- Publication:
-
AAS/High Energy Astrophysics Division #4
- Pub Date:
- April 1999
- Bibcode:
- 1999HEAD....4.1307D