AAS 196th Meeting, June 2000
Session 21. Supermassive Blackhole Research and Advances with STIS
Topical Session Oral, Tuesday, June 6, 2000, 8:30-10:00am, 10:45am-12:30pm, 2:00-3:30pm, 3:45-5:30pm, Lilac Ballroom

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[21.13] The Nuclear Dynamics of NGC4742

M. E. Kaiser (JHU), G. A. Bower, R. F. Green (NOAO/KPNO), STIS IDT Team

We present STIS high spatial resolution long-slit spectroscopy of the nuclear region of NGC4742 as part of the STIS GTO program dedicated to understanding the demographics of supermassive central black holes in galaxies.

NGC4742 is a relavely nearby (13Mpc), early-type galaxy. It was chosen as a low luminosity (MV=-19.32) candidate in the WFPC-I program to explore galaxy core structure as a function of luminosity (Lauer et al.~1995). The WFPC-I observations exhibit no flattening of the surface brightness profiles into the resolution limit of the observations. Consequently, NGC4742 has been classified as a ``power-law'' galaxy based upon its steep surface brightness profile interior to its break radius, rb=1.4\arcsec (Lauer et al.~1995, Byun et al.~1996).

Using HST/STIS and KPNO/4m long-slit spectroscopy of the CaII triplet near 8600Å, we have mapped the nuclear gravitational potential in this galaxy using the Fourier Correlation Quotient method. Our data exhibit a steep velocity rise in the inner 0.2\arcsec of NGC4742 suggesting that this galaxy contains a central massive black hole. Preliminary analysis indicates that this central mass is consistent with the empirical black hole mass to bulge luminosity relation (Richstone et al.~1998). Detailed modelling of the stellar velocities using three-integral axisymmetric models (Gebhardt et al.~2000) will be employed to obtain the central mass contained within this radius.

Support for this work was provided by NAS5-30403.

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