THE M {sub BH}-L {sub SPHEROID} RELATION AT HIGH AND LOW MASSES, THE QUADRATIC GROWTH OF BLACK HOLES, AND INTERMEDIATE-MASS BLACK HOLE CANDIDATES

Journal Article · Wed Feb 20 04:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/764/2/151· OSTI ID:22167731

Graham, Alister W.; Scott, Nicholas ^[1]

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1. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)

From a sample of 72 galaxies with reliable supermassive black hole masses M {sub bh}, we derive the M {sub bh}-(host spheroid luminosity, L) relation for (1) the subsample of 24 core-Sersic galaxies with partially depleted cores, and (2) the remaining subsample of 48 Sersic galaxies. Using K{sub s} -band Two Micron All Sky Survey data, we find the near-linear relation M {sub bh}{proportional_to}L {sup 1.10{+-}0.20} {sub K{sub s}} for the core-Sersic spheroids thought to be built in additive dry merger events, while we find the relation M {sub bh}{proportional_to}L {sup 2.73{+-}0.55}{sub K{sub s}} for the Sersic spheroids built from gas-rich processes. After converting literature B-band disk galaxy magnitudes into inclination- and dust-corrected bulge magnitudes, via a useful new equation presented herein, we obtain a similar result. Unlike with the M {sub bh}-(velocity dispersion) diagram, which is also updated here using the same galaxy sample, it remains unknown whether barred and non-barred Sersic galaxies are offset from each other in the M {sub bh}-L diagram. While black hole feedback has typically been invoked to explain what was previously thought to be a nearly constant M {sub bh}/M {sub Spheroid} mass ratio of {approx}0.2%, we advocate that the near-linear M {sub bh}-L and M {sub bh}-M {sub Spheroid} relations observed at high masses may have instead arisen largely from the additive dry merging of galaxies. We argue that feedback results in a dramatically different scaling relation, such that black hole mass scales roughly quadratically with the spheroid mass in Sersic galaxies. We therefore introduce a revised cold-gas 'quasar' mode feeding equation for semi-analytical models to reflect what we dub the quadratic growth of black holes in Sersic galaxies built amidst gas-rich processes. Finally, we use our new Sersic M {sub bh}-L equations to predict the masses of candidate intermediate mass black holes in almost 50 low-luminosity spheroids containing active galactic nuclei, finding many masses between that of stellar mass black holes and supermassive black holes.

• OSTI ID: 22167731
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 764; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
BLACK HOLES
COSMIC DUST
DIAGRAMS
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
INCLINATION
LUMINOSITY
MASS
QUASARS