The Optical–uv Emissivity of Quasars: Dependence on Black Hole Mass and Radio Loudness

Shankar, Francesco; Calderone, Giorgio; Knigge, Christian; Matthews, James H.; Buckland, Rachel; Hryniewicz, Krzysztof; Sivakoff, G. R.; Dai, Xinyu; Richardson, K. M.; Riley, J. A.; Gray, J.; Franca, F. La; Altamirano, D.; Croston, J. H.; Gandhi, P.; Hönig, Sebastian; McHardy, I. M.; Middleton, Matthew

doi:10.3847/2041-8205/818/1/l1

Cited by 32 publications

(32 citation statements)

References 48 publications

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“…This result is consistent with previous work that found RL quasars to be redder (Brotherton et al 2001;Labita et al 2008;Shankar et al 2016). We confirm this trend holds also when the samples are being matched in M BH , L 5100 and z.…”

Section: Rl and Rq Composite Spectrasupporting

confidence: 93%

Evidence for Higher Black Hole Spin in Radio-loud Quasars

Schulze

Done

et al. 2017

ApJ

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Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACT One of the major unsolved questions on the understanding of the AGN population is the origin of the dichotomy between radio-quiet and radio-loud quasars. The most promising explanation is provided by the spin paradigm, which suggests radio-loud quasars have higher black hole spin. However, the measurement of black hole spin remains extremely challenging. We here aim at comparing the mean radiative efficiencies of carefully matched samples of radio-loud and radio-quiet SDSS quasars at 0.3 < z < 0.8. We use the [O III] luminosity as an indirect average tracer of the ionizing continuum in the extreme-UV regime where differences in the SED due to black hole spin are most pronounced. We find that the radio-loud sample shows an enhancement in [O III] line strength by a factor of at least 1.5 compared to a radio-quiet sample matched in redshift, black hole mass and optical continuum luminosity or accretion rate. We argue that this enhancement is caused by differences in the SED, suggesting higher average bolometric luminosities at fixed accretion rate in the radio-loud population. This suggests that the radio-loud quasar population has on average systematically larger radiative efficiencies and therefore higher black hole spin than the radio-quiet population, providing observational support for the black hole spin paradigm.

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Section: Rl and Rq Composite Spectrasupporting

confidence: 93%

Evidence for Higher Black Hole Spin in Radio-loud Quasars

Schulze

Done

et al. 2017

ApJ

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“…Most importantly, we find ( Figure 5) that reproducing the raw observed relation between galaxy stellar masses and the dynamically inferred masses of inactive black holes requires a radiative efficiency ε ∼ 0.02, well below theoretical expectations for thin accretion disks and values inferred from UV spectral energy distribution fitting (e.g., Davis & Laor 2011;Trakhtenbrot 2014;Capellupo et al 2015a;Shankar et al 2016b) and X-ray reflection analysis (Reynolds 2014). Higher bolometric corrections or significant fractions of obscured accretion can increase the inferred ε, but we still find ε 0.05 for reasonable assumptions about these uncertainties ( Figure 6).…”

Section: Discussionmentioning

confidence: 59%

“…A non-negligible obscured AGN fraction f for galaxies in our stellar mass range (e.g., Harrison et al 2016;Ananna et al 2019) would increase our inferred ε by a factor ∼ (1 + f ), so at face value our results favour ε 0.15 − 0.20, implying high characteristic spin parameters a 0.9. Most direct measurements of black hole spins from X-ray reflection spectroscopy favour a 0.5 (see, for example, Table 1 in Zhang & Lu 2019), a finding further corroborated by UV spectral energy distribution modelling (e.g., Capellupo et al 2015a;Shankar et al 2016b). Future observations and modelling can reduce uncertainties in bolometric corrections and the contribution of obscured accretion.…”

Section: Discussionmentioning

confidence: 79%

Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei

Shankar

Weinberg

Marsden

et al. 2019

Monthly Notices of the Royal Astronomical Society

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The masses of supermassive black holes at the centres of local galaxies appear to be tightly correlated with the mass and velocity dispersions of their galactic hosts. However, the local M bh -M star relation inferred from dynamically measured inactive black holes is up to an order-of-magnitude higher than some estimates from active black holes, and recent work suggests that this discrepancy arises from selection bias on the sample of dynamical black hole mass measurements. In this work we combine X-ray measurements of the mean black hole accretion luminosity as a function of stellar mass and redshift with empirical models of galaxy stellar mass growth, integrating over time to predict the evolving M bh -M star relation. The implied relation is nearly independent of redshift, indicating that stellar and black hole masses grow, on average, at similar rates. Matching the de-biased local M bh -M star relation requires a mean radiative efficiency ε 0.15, in line with theoretical expectations for accretion onto spinning black holes. However, matching the "raw" observed relation for inactive black holes requires ε ∼ 0.02, far below theoretical expectations. This result provides independent evidence for selection bias in dynamically estimated black hole masses, a conclusion that is robust to uncertainties in bolometric corrections, obscured active black hole fractions, and kinetic accretion efficiency. For our fiducial assumptions, they favour moderate-to-rapid spins of typical supermassive black holes, to achieve ε ∼ 0.12 − 0.20. Our approach has similarities to the classic Soltan analysis, but by using galaxy-based data instead of integrated quantities we are able to focus on regimes where observational uncertainties are minimized.

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“…It is also observationally difficult to isolate the intrinsic disk continuum due to line emission, host-galaxy starlight, and internal reddening, and the emission peak is generally unobservable due to absorption by intervening hydrogen. After accounting for these effects, it is sometimes possible to fit the observed spectrum with disk models (e.g., Capellupo et al 2015), but this is not always the case (e.g., Shankar et al 2016). Alternative attempts to isolate the continuum emission have made use of polarimetry (Kishimoto et al 2004(Kishimoto et al , 2008 and difference spectra/color variability (Wilhite et al 2005;Pereyra et al 2006;Schmidt et al 2012), but the interpretation of these data is not straightforward (e.g., Kokubo 2015Kokubo , 2016.…”

Section: Introductionmentioning

confidence: 99%

Continuum Reverberation Mapping of the Accretion Disks in Two Seyfert 1 Galaxies

Fausnaugh

Starkey

Horne

et al. 2018

ApJ

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We present optical continuum lags for two Seyfert 1 galaxies, MCG+08-11-011 and NGC 2617, using monitoring data from a reverberation mapping campaign carried out in 2014. Our light curves span the ugriz filters over four months, with median cadences of 1.0 and 0.6 days for MCG+08-11-011 and NGC 2617, respectively, combined with roughly daily X-ray and near-UV data from Swift for NGC 2617. We find lags consistent with geometrically thin accretion-disk models that predict a lag-wavelength relation of τ ∝ λ 4/3. However, the observed lags are larger than predictions based on standard thin-disk theory by factors of 3.3 for MCG+08-11-011 and 2.3 for NGC 2617. These differences can be explained if the mass accretion rates are larger than inferred from the optical luminosity by a factor of 4.3 in MCG+08-11-011 and a factor of 1.3 in NGC 2617, although uncertainty in the SMBH masses determines the significance of this result. While the X-ray variability in NGC 2617 precedes the UV/optical variability, the long (2.6 day) lag is problematic for coronal reprocessing models.

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The Optical–uv Emissivity of Quasars: Dependence on Black Hole Mass and Radio Loudness

Cited by 32 publications

References 48 publications

Evidence for Higher Black Hole Spin in Radio-loud Quasars

Evidence for Higher Black Hole Spin in Radio-loud Quasars

Probing black hole accretion tracks, scaling relations, and radiative efficiencies from stacked X-ray active galactic nuclei

Continuum Reverberation Mapping of the Accretion Disks in Two Seyfert 1 Galaxies

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