Ultraviolet variability of quasars: dependence on the accretion rate

Abstract

We compiled a catalogue of about 4000 SDSS quasars including individual estimators V for the variability strength, virial black hole masses M, and mass accretion rates dM/dt from the Davis-Laor scaling relation. We confirm significant anti-correlations between V and dM/dt, the Eddington ratio, and the bolometric luminosity L, respectively. 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 with M and show that this trend is most likely produced by selection effects in combination with the mass errors and the use of the scaling relation for dM/dt. The anti-correlations found for V cannot be explained in such a way. The strongest anti-correlation is found with dM/dt. However, it is difficult to decide which of the quantities (L, Eddington ratio, dM/dt) is intrinsically correlated with V and which of the observed correlations are produced by the relations between these quantities. A V-dM/dt anti-correlation is qualitatively expected for the strongly inhomogeneous accretion disks. We argue that several observed variability properties 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.

16 pages, 10 figures; accepted for publication in Astronomy and Astrophysics; the full catalogue is only available in electronic form at CDS

References in corpus (14)

• A Catalog of Quasar Properties from SDSS DR7
• Modeling the Time Variability of SDSS Stripe 82 Quasars as a Damped Random Walk
• Stability of Relativistic Jets from Rotating, Accreting Black Holes via Fully Three-Dimensional Magnetohydrodynamic Simulations
• Global General Relativistic MHD Simulation of a Tilted Black-Hole Accretion Disk
• Fe II Emission in 14 Low-Redshift Quasars: I - Observations
• Sizes and Temperature Profiles of Quasar Accretion Disks from Chromatic Microlensing
• Quasar Accretion Disks Are Strongly Inhomogeneous
• Light and Motion in SDSS Stripe 82: The Catalogues
• The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared
• On the variability of quasars: a link between Eddington ratio and optical variability?
• The UV Continuum of Quasars: Models and SDSS Spectral Slopes
• Evidence for Rapidly Spinning Black Holes in Quasars
• The dependence of quasar variability on black hole mass
• An accretion disc model for quasar optical variability

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