The Mass Distribution in the Elliptical Galaxy Ngc 3377: Evidence for a 2× 10-m⊙ Black Hole

This paper is a study of the mass distribution in the central 35 ≃ 1.7 kpc of the E5 galaxy NGC 3377. Stellar rotation velocity and velocity dispersion profiles (seeing σ∗ = 0. 20 – 0. 56) and V -band surface photometry (σ∗ = 0. 20 – 0. 26) have been obtained with the Canada-France-Hawaii Telescope. NGC 3377 is kinematically similar to M32: the central kinematic gradients are steep. There is an unresolved central rise in rotation velocity to V = 110± 3 km s (internal error) at r = 1. 0. The apparent velocity dispersion rises from 95± 2 km s at 1. 0 ≤ r < 4 to 178± 10 km s at the center. To search for a central black hole, we derive three-dimensional velocity and velocity dispersion fields that fit the above observations and Hubble Space Telescope surface photometry after projection and seeing convolution. Isotropic models imply that the mass-to-light ratio rises by a factor of∼ 4 at r < 2 toM/LV