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[*] On the stellar kinematical evidence for massive black holes in galactic nuclei expected with HST
van der Marel R.P.
ApJ Letters, 432, L91-L94, 1994
© 1994. The American Astronomical Society. All Rights Reserved.

[*] Citations to this paper in the ADS

The central line-of-sight velocity distribution, or `velocity profile' (VP), of a stellar system with a massive central black hole has more extended wings than a Gaussian. The importance of these wings is studied for the high spatial resolution absorption line spectra that are now being obtained with HST. As an example, the central VP is calculated for an isotropic dynamical model for M87 with a 5 x 10^9 solar mass black hole, for observations through a small circular aperture of diameter D. Conventional techniques for the analysis of galaxy spectra that assume Gaussian VPs strongly underestimate the true velocity dispersion (for D = 0.1 arcsec, by more than a factor 2). At HST resolution it is thus essential to model VP deviations from a Gaussian. An actual VP shape measurement will strongly constrain any dynamical model, but might be difficult to obtain in practice.

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Last modified December 8, 1998.
Roeland van der Marel, marel@stsci.edu.
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