NOAO >   Observing Info >   Approved Programs >   2006A-0246

# Proposal Information for 2006A-0246

PI: Tod R. Lauer, NOAO, lauer@noao.edu
Address: P. O. Box 26732, Tucson, AZ 85726, USA

CoI: Karl Gebhardt, University of Texas at Austin
CoI: Doug Richstone, University of Michigan
CoI: Sandra M. Faber, University of California, Santa Cruz
CoI: Scott Tremaine, Princeton University

Title: The Most Massive Black Holes in the Local Universe

Abstract: We propose to obtain high spatial-resolution NIR spectra of the centers of brightest cluster galaxies to detect and weigh'' their nuclear black holes. Black holes have not yet been searched for in such high-mass galaxies; the required spatial resolution and sensitivity is only now becoming available via the introduction of AO-fed spectrographs on 10m class telescopes. Predicted black hole masses, M_\bullet, from the M_\bullet-\sigma versus M_\bullet-L (luminosity) relationship conflict strongly in this galaxy mass range. The core-scouring'' model for the origin of the large cores of the BCG seen in \it HST imagery favor the higher M_\bullet predicted from the M_\bullet-L relationship. If so, the present epoch mass density of black holes with M_\bullet>10^9M_\odot may be one to two orders of magnitude higher than that estimated from the M_\bullet-\sigma relationship. The three target galaxies all have M_\bullet\gtrsim3\times10^9M_\odot predicted from the M_\bullet-L relationship. The observations proposed may substantially boost the number of black holes observed in this mass range, and indicate which relationship, M_\bullet-\sigma or M_\bullet- L, better predicts M_\bullet for the most massive galaxies.

National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360

 NOAO >   Observing Info >   Approved Programs >   2006A-0246