Year: 2013
Type: article
Abstract: New kinematic data and modeling efforts in the past few years have substantially expanded and revised dynamical measurements of black hole masses ( M • ) at the centers of nearby galaxies. Here we compile an updated sample of 72 black holes and their host galaxies, and present revised scaling relations between M • and stellar velocity dispersion (σ), V -band luminosity ( L ), and bulge stellar mass ( M bulge ), for different galaxy subsamples. Our best-fitting power-law relations for the full galaxy sample are log 10 ( M • ) = 8.32 + 5.64log 10 (σ/200 km s −1 ), log 10 ( M • ) = 9.23 + 1.11log 10 ( L /10 11 L ☉ ), and log 10 ( M • ) = 8.46 + 1.05log 10 ( M bulge /10 11 M ☉ ). A log-quadratic fit to the M • –σ relation with an additional term of β 2 [log 10 (σ/200 km s −1 )] 2 gives β 2 = 1.68 ± 1.82 and does not decrease the intrinsic scatter in M • . Including 92 additional upper limits on M • does not change the slope of the M • –σ relation. When the early- and late-type galaxies are fit separately, we obtain similar slopes of 5.20 and 5.06 for the M • –σ relation but significantly different intercepts— M • in early-type galaxies are about two times higher than in late types at a given sigma. Within early-type galaxies, our fits to M • (σ) give M • that is about two times higher in galaxies with central core profiles than those with central power-law profiles. Our M • – L and M • – M bulge relations for early-type galaxies are similar to those from earlier compilations, and core and power-law galaxies yield similar L - and M bulge -based predictions for M • . When the conventional quadrature method is used to determine the intrinsic scatter in M • , our data set shows weak evidence for increased scatter at M bulge < 10 11 M ☉ or L V < 10 10.3 L ☉ , while the scatter stays constant for 10 11 < M bulge < 10 12.3 M ☉ and 10 10.3 < L V < 10 11.5 L ☉ . A Bayesian analysis indicates that a larger sample of M • measurements would be needed to detect any statistically significant trend in the scatter with galaxy properties.
Source: The Astrophysical Journal
Authors: Nicholas J. McConnell, Chung-Pei Ma
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funder: National Science Foundation
OpenAlex ID: W1990401433