2009ApJ...695.1577G

We report five new measurements of central black hole masses based on Space Telescope Imaging Spectrograph and Wide Field Planetary Camera 2 observations with the Hubble Space Telescope (HST) and on axisymmetric, three-integral, Schwarzschild orbit-library kinematic models. We selected a sample of galaxies within a narrow range in velocity dispersion that cover a range of galaxy parameters (including Hubble type and core/power-law surface density profile) where we expected to be able to resolve the galaxy's sphere of influence based on the predicted value of the black hole mass from the M-σ relation. We find masses for the following galaxies: NGC 3585, M_BH= 3.4^+1.5_–0.6 x10⁸ M_☉; NGC 3607, M_BH= 1.2^+0.4_–0.4x10⁸ M_☉; NGC 4026, M_BH= 2.1^+0.7_–0.4x10⁸ M_☉; and NGC 5576, M_BH = 1.8^+0.3_–0.4x10⁸ M_☉, all significantly excluding M_BH = 0. For NGC 3945, M_BH= 9⁺¹⁷_–21x10⁶ M_☉, which is significantly below predictions from M-σ and M-L relations and consistent with M _BH= 0, though the presence of a double bar in this galaxy may present problems for our axisymmetric code.