Cosmological Evolution of Supermassive Black Holes. Ii. Evidence for Downsizing of Spin Evolution

Li, Yan-Rong; Wang, Jian-Min; Ho, Luis C.

doi:10.1088/0004-637x/749/2/187

Cited by 47 publications

(61 citation statements)

References 93 publications

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“…Estimates of the average radiative efficiency using different methods yieldη > ∼ 0.1 (Soltan 1982;Elvis et al 2002;Yu & Tremaine 2002;Wang et al 2006;Davis & Laor 2011;hereafter DL11). Individual values of η may not only scatter over about one order of magnitude (depending on the accretion history from chaotic to coherent accretion; see Dotti et al 2013) but may also depend on M. A correlation between spin and mass was predicted by numerical simulations of the BH growth (Dotti et al 2013) and seems to be present in different quasar samples (DL11; Laor & Davis 2011a;Li et al 2012;Raimundo et al 2012;Chelouche 2013; see also below). At highest temperatures, the T profile is determined by r in (Eq.…”

Section: Scaling Relationsmentioning

confidence: 94%

Ultraviolet variability of quasars: dependence on the accretion rate

Meusinger

Weiss

2013

A&A

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Aims. Although the variability in the ultraviolet and optical domain is one of the major characteristics of quasars, the dominant underlying mechanisms are still poorly understood. There is a broad consensus on the relationship between the strength of the variability and such quantities as time-lag, wavelength, luminosity, and redshift. However, evidence on a dependence on the fundamental parameters of the accretion process is still inconclusive. This paper is focused on the correlation between the ultraviolet quasar long-term variability and the accretion rate. Methods. We compiled a catalogue of about 4000 quasars including individual estimators for the variability strength derived from the multi-epoch photometry in the SDSS Stripe 82, virial black hole masses M derived from the Mg  line, and mass accretion ratesṀ from the Davis-Laor scaling relation. Several statistical tests were applied to evaluate the correlations of the variability with luminosity, mass, Eddington ratio, and accretion rate. Results. We confirm the existence of significant anti-correlations between the variability estimator V and the accretion rateṀ, the Eddington ratio ε, and the bolometric luminosity L bol , respectively. The Eddington ratio is tightly correlated withṀ. A weak, statistically not significant positive trend is indicated for the dependence of V on M. As a side product, we find a strong correlation of the radiative efficiency η with M in our sample. We show via numerical simulations that this trend is most likely produced by selection effects in combination with the mass errors and the use of the scaling relation forṀ. The anti-correlations of V withṀ, ε, and L bol cannot be explained in such a way. The strongest anti-correlation is found between V andṀ. However, it is difficult to decide which of the quantities L, ε, andṀ is intrinsically correlated with V and which of the observed correlations of V are produced by the L − ε −Ṁ relation. A V −Ṁ anti-correlation is qualitatively expected for the strongly inhomogeneous accretion disks. We argue that the observed amplitudes of the variability at far-UV wavelengths, the stochastic nature of variability, and the variability time-scales are not adequately explained by the simple multi-temperature black-body model of a standard disk and suggest to check whether the strongly inhomogeneous disk model is capable of reproducing these observations better.

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Section: Scaling Relationsmentioning

confidence: 94%

Ultraviolet variability of quasars: dependence on the accretion rate

Meusinger

Weiss

2013

A&A

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“…Detailed considerations also indicate that η may depend significantly upon SMBH mass and redshift (e.g., Li et al 2012;Shankar 2013;Ueda et al 2014).…”

Section: The So Ltan Argument For X-ray Selected Agnsmentioning

confidence: 99%

Cosmic X-ray surveys of distant active galaxies

Brandt

Alexander

2015

Astron Astrophys Rev

318

227

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We review results from cosmic X-ray surveys of active galactic nuclei (AGNs) over the past ≈ 15 yr that have dramatically improved our understanding of growing supermassive black holes in the distant universe. First, we discuss the utility of such surveys for AGN investigations and the capabilities of the missions making these surveys, emphasizing Chandra, XMM-Newton, and NuSTAR. Second, we briefly describe the main cosmic X-ray surveys, the essential roles of complementary multiwavelength data, and how AGNs are selected from these surveys. We then review key results from these surveys on the AGN population and its evolution ("demographics"), the physical processes operating in AGNs ("physics"), and the interactions between AGNs and their environments ("ecology"). We conclude by describing some significant unresolved questions and prospects for advancing the field.

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“…We argue that the use of a constant in AGNs/QSOs is appropriate as follows: (1) is determined mainly by the spins of MBHs in the standard disk accretion scenario; (2) the majority of the AGNs/QSOs are accreting via thin disks with high Eddington ratios ( 0.1); and (3) the spins of individual MBHs can quickly reach an equilibrium value and stay at that value for most of the AGN lifetime as suggested by theoretical models (e.g., Volonteri et al 2005;Shapiro 2005;Hawley et al 2007;Maio et al 2012), which suggests a roughly constant at all redshifts. Note that according to recent observations, some authors such as Davis & Laor (2011), Martínez-Sansigre & Rawlings (2011), and Li et al (2012b introduced a dependence of on the redshift or MBH mass. However, these results may be due only to some observational biases (e.g., Raimundo et al 2012) and need further investigation.…”

Section: Mass-to-energy Conversion Efficiency In Agns/qsosmentioning

confidence: 99%

THE COSMIC EVOLUTION OF MASSIVE BLACK HOLES AND GALAXY SPHEROIDS: GLOBAL CONSTRAINTS AT REDSHIFTz≲ 1.2

Zhang

2012

ApJ

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We study observational constraints on the cosmic evolution of the relationships between massive black hole (MBH) mass (M • ) and stellar mass (M * ,sph ; or velocity dispersion σ ) of a host galaxy/spheroid. Assuming that the M • -M * ,sph (or M • -σ ) relation evolves with redshift as ∝ (1 + z) Γ , the MBH mass density can be obtained from either the observationally determined galaxy stellar mass functions or velocity dispersion distribution functions over redshift z ∼ 0-1.2 for any given Γ. The MBH mass density at different redshifts can also be inferred from the luminosity function of QSOs/active galactic nuclei (AGNs) provided the radiative efficiency is known. By matching the MBH density inferred from galaxies to that obtained from QSOs/AGNs, we find that Γ = 0.64 +0.27 −0.29 for the M • -M * ,sph relation and Γ = −0.21 +0.28 −0.33 for the M • -σ relation, and = 0.11 +0.04 −0.03 . Our results suggest that MBH mass growth precedes bulge mass growth but that the galaxy velocity dispersion does not increase with the mass growth of the bulge after nuclear activity is quenched, which is roughly consistent with the two-phase galaxy formation scenario proposed by Oser et al. in which a galaxy roughly doubles its mass after z = 1 due to accretion and minor mergers while its velocity dispersion drops slightly.

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Cosmological Evolution of Supermassive Black Holes. Ii. Evidence for Downsizing of Spin Evolution

Cited by 47 publications

References 93 publications

Ultraviolet variability of quasars: dependence on the accretion rate

Ultraviolet variability of quasars: dependence on the accretion rate

Cosmic X-ray surveys of distant active galaxies

THE COSMIC EVOLUTION OF MASSIVE BLACK HOLES AND GALAXY SPHEROIDS: GLOBAL CONSTRAINTS AT REDSHIFTz≲ 1.2

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