Populating the Galaxy Velocity Dispersion: Supermassive Black Hole Mass Diagram, A Catalogue of (Mbh, σ) Values

Abstract

AbstractAn updated catalogue of 76 galaxies, with direct measurements of supermassive black-hole mass (Mbh) plus, when available, the central velocity dispersion (σ0) of their host bulge is provided. Fifty of these mass measurements are considered reliable, while the others remain somewhat uncertain at this time. An additional nine stellar systems, including one stellar cluster and three globular clusters, are listed as hosting potential intermediate mass black holes <106M⊙.With this larger data set, the demographics within the Mbh–σ0 diagram are briefly explored. Many barred galaxies are shown to be offset from the Mbh–σ0 relation defined by the non-barred galaxies, in the sense that their velocity dispersions are too high. Furthermore, including 88 AGN with black-hole mass estimates from reverberation mapping studies, we speculate that barred AGN may follow this same general trend. We also show that some AGN with σ0 < 100 km s−1 tend to reside up to (∼0.6 dex) ∼1.0 dex above the (barless) Mbh–σ0 relation. Finally, it is shown that ‘core galaxies’ appear not to define an additional subdivision of the Mbh–σ0 diagram, although improved methods for measuring σ0 values may be valuable.