NGC 4435: a bulge-dominated galaxy with an unforeseen low-mass central black hole

We present the ionized gas kinematics of the SB0 galaxy NGC 4435 from spectra obtained with the Space Telescope Imaging Spectrograph. This galaxy has been selected on the basis of its ground-based spectroscopy, for displaying a position-velocity diagram consistent with the presence of a circumnuclear Keplerian disc rotating around a supermassive black hole (SMBH). We obtained the Hα and [NII]λ6583 kinematics in the galaxy nucleus along the major axis and two parallel offset positions. We built a dynamical model of the gaseous disc taking into account the whole bi-dimensional velocity field and the instrumental setup. For the mass of the central SMBH, we found an upper limit of 7.5 × 10^6 M_solar at the 3σ level. This indicates that the mass of the SMBH of NGC 4435 is lower than the one expected from the M_BH-σ_c (5 × 10^7 M_solar) and near-infrared M_BH-L_bulge (4 × 10^7 M_solar) relationships.