Program: GS-2004A-SV-8

Black holes are believed to be essential components of galaxies, and their evolutionary states appear to be closely linked to those of their hosts. However our knowledge does not go much beyond this, since given the more than 20 theoretical models that predict a correlation between black hole and its host, none have been excluded with the current data. Centaurus A (NGC5128) will play an important role in helping the situation, since GNIRS will be able to measure a black hole mass to about 20% accuracy from the stellar dynamical data. The reasons that Cen A is important are that 1) it has an active nucleus which means that its black hole is currently being fed, 2) it has a central gas disk that tells us about the enclosed mass and how material is funneled into the center, and 3) it is our nearest elliptical galaxy and thus we can obtain the best spatial resolution possible. We have not been able to study the cental regions in Cen A previously because of its significant amount of dust. We will use the CO bandhead at 2.3um to measure the central dynamics, this setup will open up a new era for black hole research as it will allow us to probe the most interesting galaxies, and Cen A is the prime example.