Fitting improved accretion disk models to the multiwavelength continua of quasars and active galactic nuclei

Sun, Wei‐Hsin; Malkan, Matthew A.

doi:10.1086/167986

Cited by 271 publications

(235 citation statements)

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“…If true for other radioquiet QSOs, this implies that Ðts to the big blue bump, which include a synchrotron power law, may be Ñawed (Sun & Malkan 1989 ;Laor 1990). Starburst and host galaxy contributions to the mid-IR emission are ruled out based on the low radio Ñux, small size, and large IR luminosity, leaving hot dust as the only viable model for the IR emission in the Einstein Cross.…”

Section: Discussionmentioning

confidence: 99%

Keck Mid‐Infrared Imaging of QSO 2237+0305

Agol

Jones

Blaes

2000

ApJ

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Using the Long Wavelength Spectrometer on Keck, we have imaged the gravitationally lensed radioquiet quasi-stellar object QSO 2237]0305 at 8.9 and 11.7 km for the Ðrst time. The mid-IR Ñux ratios are inconsistent with the optical Ñux ratios but agree with the radio Ñux ratios and with some published gravitational lens models. These Ñux ratios indicate that the IR emission is not a †ected by microlensing, which rules out the synchrotron emission model. The IR emission is likely produced by hot dust extended on a length scale of more than 0.03 pc. The spectral energy distribution further implies a narrow range of dust temperatures, suggesting that the dust may be located in a shell extending between D1 and 3 pc from the nucleus and intercepting about half of the QSO luminosity.

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Section: Discussionmentioning

confidence: 99%

Keck Mid‐Infrared Imaging of QSO 2237+0305

Agol

Jones

Blaes

2000

ApJ

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“…If we include also relativistic effects of the disc inclination, including Doppler boosting and gravitational focusing, by assuming that the accretion disc shares the same behavior as that seen in AGNs (see Sun & Malkan 1989), the mass might rise to M = (12 ± 1) M .…”

Section: Evaluation Of the Mass Of M 33 X-8mentioning

confidence: 99%

XMM–Newtonobservations of the ultraluminous nuclear X-ray source in M 33

Foschini¹,

Rodríguez²,

Fuchs³

et al. 2004

A&A

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Abstract. We present observations with XMM-Newton of M 33 X-8, the ultraluminous X-ray source (L 0.5−10 keV ≈ 2×10 39 erg/s) closest to the centre of the galaxy. The best-fit model is similar to the typical model of Galactic black holes in very high state. Comparison with previous observations indicates that the source is still in a very high state after about 20 years of observations. No state transition has been observed even during the present set of XMM-Newton observations. We estimate the lower limit of the mass of the black hole >6 M , but with proper parameters taking into account different effects, the best estimate becomes 12 M . Our analysis favours the hypothesis that M 33 X-8 is a stellar mass black hole candidate, in agreement with the findings of other authors. In addition, we propose a different model where the high luminosity of the source is likely to be due to orientation effects of the accretion disc and anisotropies in the Comptonized emission.

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“…Quasar accretion disks cannot be spatially resolved with ordinary telescopes, so we have been forced to test accretion physics through time variability (e.g., Vanden Berk et al 2004;Sergeev et al 2005;Cackett et al 2007) and spectral modeling (e.g., Sun & Malkan 1989;Collin et al 2002;Bonning et al 2007). One notable success is the use of reverberation mapping (e.g., Peterson et al 2004) of quasar broad-line emission to calibrate the relation between emission line widths and black hole masses.…”

Section: Introductionmentioning

confidence: 99%

The Quasar Accretion Disk Size-Black Hole Mass Relation

Morgan

Kochanek

Morgan

et al. 2010

ApJ

346

484

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We use the microlensing variability observed for 11 gravitationally lensed quasars to show that the accretion disk size at a rest-frame wavelength of 2500 Å is related to the black hole mass by log(R 2500 /cm) = (15.78 ± 0.12) + (0.80 ± 0.17) log(M BH /10 9 M ). This scaling is consistent with the expectation from thin-disk theory (R ∝ M 2/3 BH ), but when interpreted in terms of the standard thin-disk model (T ∝ R −3/4 ), it implies that black holes radiate with very low efficiency, log(η) = −1.77 ± 0.29 + log(L/L E ), where η = L/(Ṁc 2 ). Only by making the maximum reasonable shifts in the average inclination, Eddington factors, and black hole masses can we raise the efficiency estimate to be marginally consistent with typical efficiency estimates (η ≈ 10%). With one exception, these sizes are larger by a factor of ∼4 than the size needed to produce the observed 0.8 μm quasar flux by thermal radiation from a thin disk with the same T ∝ R −3/4 temperature profile. While scattering a significant fraction of the disk emission on large scales or including a large fraction of contaminating line emission can reduce the size discrepancy, resolving it also appears to require that accretion disks have flatter temperature/surface brightness profiles.

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Fitting improved accretion disk models to the multiwavelength continua of quasars and active galactic nuclei

Cited by 271 publications

References 0 publications

Keck Mid‐Infrared Imaging of QSO 2237+0305

Keck Mid‐Infrared Imaging of QSO 2237+0305

XMM–Newtonobservations of the ultraluminous nuclear X-ray source in M 33

The Quasar Accretion Disk Size-Black Hole Mass Relation

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