The demography of supermassive black holes: Growing monsters at the heart of galaxies

Abstract. A toy model of the population of numerous non-identical extragalactic sources of ultra-highenergy cosmic rays is presented. In the model, the acceleration of cosmic-ray particles is direct (not diffusive) and takes place in magnetospheres of supermassive black holes in galactic nuclei, the key parameter of acceleration being the black-hole mass. We use astrophysical data to describe the population of these cosmic-ray accelerators and confront the model with cosmic-ray and gamma-ray data.

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“…The systematic uncertainties of the mass function may be judged from Ref. [21] and are well within the overall precision of our toy model.…”

Section: Population Of the Sources And The Observed Spectrumsupporting

confidence: 69%

Constraints on direct acceleration of UHECRs in astrophysical sources

Kalashev

Ptitsyna

Troitsky

2013

EPJ Web of Conferences

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“…Indeed, nuclear kinematics of a number of nearby galaxies show the clear signature of a central mass concentration, beyond what can be attributed to the observed stellar population ⋆ E-mail: F.Shankar@soton.ac.uk in the nuclear regions. Black hole masses, M bh , are found to correlate with several global properties of their host galaxies (see, e.g., Ferrarese & Ford 2005;Shankar 2009; Kormendy & Ho 2013;Graham 2016, for reviews), including the stellar and/or bulge mass, velocity dispersion, σ, luminosity, light concentration or Sérsic index (e.g., Magorrian et al 1998;Richstone et al 1998 Kormendy & Ho 2013;McConnell & Ma 2013;Scott et al 2013;Läsker et al 2014;Savorgnan & Graham 2015a;Savorgnan et al 2016;Saglia et al 2016), and the mass of the surrounding dark matter halo (e.g., Ferrarese 2002a; Baes et al 2003;Bogdán & Goulding 2015;Sabra et al 2015). However, while it is true that the number of dynamical black hole mass measurements has increased over the years, such samples still remain relatively small, of the order of ∼ 70 − 80 galaxies.…”

Section: Introductionmentioning

confidence: 99%

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

Shankar¹,

Bernardi²,

Sheth³

et al. 2016

Mon. Not. R. Astron. Soc.

Self Cite

246

369

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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 σ 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 M bh -σ relation by a factor of at least ∼ 3; the bias for the M bh -M star relation is even larger. Our Monte Carlo simulations and analysis of the residuals from scaling relations both indicate that σ is more fundamental than M star or effective radius. In particular, the M bh -M star relation is mostly a consequence of the M bh -σ and σ-M star 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 σ. Correcting for this bias suggests that the calibration factor used to estimate black hole masses in active galaxies should be reduced to values of f vir ∼ 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.

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“…This picture is supported by the detection of massive elliptical galaxies hosting all luminous, nearby QSOs (Bahcall et al 1997;McLure et al 1999). Any account of bulge formation evolution which disregards the coevolution of the central black hole -or vice versa -is fundamentally incomplete (Kauffmann & Haehnelt 2000;Shankar 2009). A continuing task is to unify different galaxy types with varied luminosities into a common evolutionary scenario or parameter space.…”

Section: Introductionmentioning

confidence: 99%

Sub-millimeter detectedz ~ 2 radio-quiet QSOs

Orellana

Nagar

et al. 2011

A&A

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Context. We present near-IR spectroscopy of a sample of luminous (M B − 27.5; L bol > 10 14 L ), sub-millimeter-detected, dusty (M d ∼ 10 9 M ), radio-quiet quasi-stellar objects (QSOs) at z ∼ 2. Aims. A primary aim is to provide a more accurate QSO redshift determination in order to trace kinematics and inflows/outflows in these sub-mm bright QSOs. Additionally, the Hα and continuum properties allow an estimation of the black hole mass and accretion rate, offering insights into the starburst-AGN connection in sub-mm bright QSOs. Methods. We measure the redshift, width, and luminosity of the Hα line, and the continuum luminosity near Hα. Relative velocity differences between Hα and rest-frame UV emission lines are used to study the presence and strength of outflows/inflows. Luminosities and line widths are used to estimate the black hole masses, bolometric luminosities, Eddington fractions, and accretion rates; these are compared to the star-formation-rate (SFR), estimated from the sub-mm derived far-infrared (FIR) luminosity. Finally our sub-mmbright QSO sample is compared with other QSO samples at similar redshifts. Results. The Hα emission line was strongly detected in all sources. Two components -a very broad ( > ∼ 5000 km s −1 ) Gaussian and an intermediate-width ( > ∼ 1500 km s −1 ) Gaussian, were required to fit the Hα profile of all observed QSOs. Narrow ( < ∼ 1000 km s −1 ) lines were not detected in the sample QSOs. The rest-frame UV emission lines in these sub-mm bright QSOs show larger than average blue-shifted velocities, potentially tracing strong -up to 3000 km s −1 -outflows in the broad line region. With the exception of the one QSO which shows exceptionally broad Hα lines, the black hole masses of the QSO sample are in the range log M BH = 9.0−9.7 and the Eddington fractions are between 0.5 and ∼1. In black hole mass and accretion rate, this sub-mm bright QSO sample is indistinguishable from the Shemmer et al. (2004, ApJ, 614, 547) optically-bright QSO sample at z ∼ 2; the latter is likely dominated by sub-mm dim QSOs. Previous authors have demonstrated a correlation, over six orders of magnitude, between SFR and accretion rate in active galaxies: the sub-mm bright QSOs lie at the upper extremes of both quantities and their SFR is an order of magnitude higher than that predicted from the correlation.

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The demography of supermassive black holes: Growing monsters at the heart of galaxies

Cited by 104 publications

References 227 publications

Constraints on direct acceleration of UHECRs in astrophysical sources

Constraints on direct acceleration of UHECRs in astrophysical sources

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

Sub-millimeter detectedz ~ 2 radio-quiet QSOs

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