Selection bias in dynamically measured supermassive black hole samples: its consequences and the quest for the most fundamental relation

By Francesco Shankar, Mariangela Bernardi, R. Sheth, L. Ferrarese, Alister W. Graham, G. Savorgnan, V. Allevato, A. Marconi, R. Laesker, A. U. O. Southampton and 11 more. 2016

193 citations recorded by the source corpus.

We compare the set of local galaxies having dynamically measured black holes with a large, unbiased sample of galaxies extracted from the Sloan Digital Sky Survey. We confirm earlier work showing that the majority of black hole hosts have significantly higher velocity dispersions ? than local galaxies of similar stellar mass. We use Monte Carlo simulations to illustrate the effect on black hole scaling relations if this bias arises from the requirement that the black hole sphere of influence must be resolved to measure black hole masses with spatially resolved kinematics. We find that this selection effect artificially increases the normalization of the Mbh–? relation by a factor of at least ?3; the bias for the Mbh–Mstar relation is even larger. Our Monte Carlo simulations and analysis of the residuals from scaling relations both indicate that ? is more fundamental than Mstar or effective radius. In particular, the Mbh–Mstar relation is mostly a consequence of the Mbh–? and ?–Mstar relations, and is heavily biased by up to a factor of 50 at small masses. This helps resolve the discrepancy between dynamically based black hole–galaxy scaling relations versus those of active galaxies. Our simulations also disfavour broad distributions of black hole masses at fixed ?. Correcting for this bias suggests that the calibration factor used to estimate black hole masses in active galaxies should be reduced to values of fvir ? 1. Black hole mass densities should also be proportionally smaller, perhaps implying significantly higher radiative efficiencies/black hole spins. Reducing black hole masses also reduces the gravitational wave signal expected from black hole mergers.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/500b574a2b7986b595b0a4635082bb6d9e25d8f3

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Citations in the corpus

The cosmic evolution of massive black holes in the Horizon-AGN simulation (2016, background): “Such galaxies, however, are a biased subsample of the real universe (see also Shankar et al. 2016).”
The NANOGrav 11 Year Data Set: Pulsar-timing Constraints on the Stochastic Gravitational-wave Background (2018, methodology): “The models in Simon & Burke-Spolaor (2016) and S16 are broadly similar, differing predominantly in the choice of SMBH–host-galaxy mass relationship, where S16 factors in potential selection biases in dynamically-measured SMBH masses (Shankar et al. 2016).”
Gravitational torque-driven black hole growth and feedback in cosmological simulations (2016, background): “Various observational studies differ regarding the normalization of the MBH–Mbulge relation, which may be biased by selection effects (Shankar et al. 2016).”
Blossoms from black hole seeds: properties and early growth regulated by supernova feedback (2016, background): “…BH in a galaxy (ignoring “normal” stellar mass BHs) has a mass estimate of ∼ 50,000 M (Baldassare et al. 2015), and was identified as a low-luminosity AGN in the dwarf galaxy RGG 118 (Reines, Greene & Geha 2013; Graham, Ciambur & Soria c© 0000 RAS, MNRAS 000, 000–000 2016; Shankar et al. 2016).”
An ALMA [C ii] Survey of 27 Quasars at z > 5.94 (2018, background): “The works by Lauer et al. (2007), Decarli et al. (2010), Schulze & Wisotzki (2014), DeGraf et al. (2015), Shankar et al. (2016), and Volonteri & Reines (2016) extensively discuss these issues.”
AGN wind scaling relations and the co-evolution of black holes and galaxies (2017, methodology): “Note that the latter ratio is consistent with the intrinsic value computed by Shankar et al. (2016) for the same .”
Universal bolometric corrections for active galactic nuclei over seven luminosity decades (2020, background): “…between the super massive black hole (SMBH) mass and the host galaxy (Magorrian et al. 1998; Tremaine et al. 2002; Marconi & Hunt 2003; but see also Shankar et al. 2016, 2019) originate (in the AGN-galaxy coevolution scenarios), an accurate knowledge of the AGN internal mechanisms, physical…”