2011ApJ...741...38G

We present Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph observations of the galaxy NGC 4382 (M85) and axisymmetric models of the galaxy to determine mass-to-light ratio (Υ_V) and central black hole mass (M_BH). We find Υ_V= 3.74±0.1 M_{x2609}/L_{x2609} and M_BH= 1.3^+5.2_- 1.2_x10⁷ M_{x2609}at an assumed distance of 17.9 Mpc, consistent with no black hole. The upper limit, M_BH< 9.6 x10⁷ M_{x2609}(2σ) or M_BH< 1.4x10⁸(3σ), is consistent with the current M-σ relation, which predicts M_BH= 8.8x10⁷ M_{x2609} at σ_e= 182 km/s, but low for the current M - L relation, which predicts M_BH= 7.8x10⁸ M_{x2609} at L_V= 8.9 x10¹⁰ L_{x2609}, V_. HST images show the nucleus to be double, suggesting the presence of a nuclear eccentric stellar disk, analogous to the Tremaine disk in M31. This conclusion is supported by the HST velocity dispersion profile. Despite the presence of this non-axisymmetric feature and evidence of a recent merger, we conclude that the reliability of our black hole mass determination is not hindered. The inferred low black hole mass may explain the lack of nuclear activity.