Program: GS-2005A-Q-38
Title: | Stellar dynamics measurement of the mass of the black hole in CentaurusA |
PI: | Niranjan Thatte |
Co-I(s): | Roger L. Davies, Davor Krajnovic, Robert Sharp, Matthias Tecza |
Abstract
Our CIRPASS near infrared integral field spectroscopic observations of
the gas kinematics in the nuclear region of Centaurus A show very
complex gas motions, casting doubt on the Keplerian rotating
disk interpretation presented by Marconi et al. (2001), based on long
slit VLT spectra. We reproduce the morphology observed by Schreier et
al. (1998) with HST/NICMOS in hydrogen recombination lines.
However, the observed kinematics point to a larger rotating/outflowing
structure, in addition to the compact disk proposed by Marconi et al.
In general, the use of gas kinematics to derive a central black hole
mass in galaxies with an active nucleus is fraught with perils, as is
well demonstrated by Verdoes-Kleijn et al. (2003) for NGC 4335.
We propose to settle the debate through a definitive mass measurement
of the nuclear black hole in Centaurus A, the nearest radio galaxy,
using stellar dynamics techniques and observations with the GNIRS
IFU. The proposed K band observations can penetrate the significant
extinction toward the nucleus, and yield 2D maps of the stellar velocity field,
truly mapping the gravitational potential in the nuclear region.
Publications using this program's data
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[data]
[ADS] GNIRS NIR Integral Field Spectroscopy of NGC 5128