Key points are not available for this paper at this time.
We investigate the differences in the M (BH) -sigma relation derived recently by Ferrarese & Merritt (2000) and Gebhardt et al. (2000). The shallower slope found by the latter authors (3. 75 vs. 4. 8) is due partly to the use of a regression algorithm that ignores measurement errors, and partly to the value of the velocity dispersion adopted for a single galaxy, the Milky Way. A steeper relation is shown to provide a better fit to black hole masses derived from reverberation mapping studies. Combining the stellar dynamical, gas dynamical, and reverberation mapping mass estimates, we derive a best-fit relation M (BH) = 1. 30 (+/- 0. 36) X 10⁸ (sigmac/200) ^4. 72 (+/- 0. 36), where M (BH) is in solar masses, and sigma in km/s.
Merritt et al. (Sat,) studied this question.