Central Surface Brightness Profiles in Brightest Cluster Galaxies
Abstract
We present results from an HST WFPC2 I-band imaging study of the centers of 81 brightest cluster galaxies (BCGs). The images show a rich variety of morphological features. We were able to derive surface brightness profiles for 60 galaxies. Of those, 88% have well-resolved cores. The remaining twelve percent have ``power-law'' profiles. Therefore, the central structure of even the brightest galaxies shows a bimodality. A correlation between the power-law BCGs and the so-called α parameter, related to the slope of the surface brightness profile at a large radius, suggests a scenario in which elliptical galaxies evolve from power-law profiles to core profiles through accretion and merging. This is consistent with theoretical scenarios which invoke the formation of massive black hole binaries during merger events.
- Publication:
-
Coevolution of Black Holes and Galaxies
- Pub Date:
- 2004
- Bibcode:
- 2004cbhg.sympE..36L