  The infrared spectrograph GNIRS on Gemini South unlocks new possibilities to
study the central black holes in dusty galaxies that have been inaccessible to
previous black hole studies. We exploit good near-infrared seeing to measure
the central black hole (BH) of Centaurus A (NGC 5128). We measure the stellar
kinematics of NGC 5128 using the region around the CO bandheads at 2.3 microns
and determine the black hole mass using orbit-based models. Black holes are
believed to be essential components of galaxies, and their evolutionary states
appear to be closely linked to those of their hosts. Our current knowledge does
not go much beyond this; galaxies such as NGC 5128 (an AGN and recent merger)
can further develop this knowledge. However, NGC 5128 and galaxies like it
contain large amounts of dust which hamper optical spectroscopy, making
near-infrared measurements an attractive alternative. We find a BH mass of
2.4e8 solar masses for an edge-on model, 1.8e8 solar masses for a model with
inclination of 45 degrees, and 1.5e8 solar masses for a model with inclination
of 20 degrees. We adopt the value for the edge-on model, which has
significantly lower chi^2. These estimates are consistent with a previous gas
dynamical estimate and are five to ten times higher than that predicted by the
correlation between BH mass and velocity dispersion. If NGC 5128 will
eventually follow the trend for quiescent galaxies, this result suggests that
its BH assembled first before its host component. NGC 5128 thus provides an
important example for our knowledge of central black holes; this technique can
be applied to other such galaxies to further explore this question.
