The Average Size and Temperature Profile of Quasar Accretion Disks

Mediavilla, E.; Jiménez-Vicente, J.; Kochanek, C. S.; Muñoz, J. A.; Motta, V.; Falco, E.; Mosquera, A. M.
Bibliographical reference

The Astrophysical Journal, Volume 783, Issue 1, article id. 47, 7 pp. (2014).

Advertised on:
3
2014
Number of authors
7
IAC number of authors
1
Citations
66
Refereed citations
60
Description
We use multi-wavelength microlensing measurements of a sample of 10 image pairs from 8 lensed quasars to study the structure of their accretion disks. By using spectroscopy or narrowband photometry, we have been able to remove contamination from the weakly microlensed broad emission lines, extinction, and any uncertainties in the large-scale macro magnification of the lens model. We determine a maximum likelihood estimate for the exponent of the size versus wavelength scaling (rs vpropλ p , corresponding to a disk temperature profile of Tvpropr –1/p ) of p=0.75^{+0.2}_{-0.2} and a Bayesian estimate of p = 0.8 ± 0.2, which are significantly smaller than the prediction of the thin disk theory (p = 4/3). We have also obtained a maximum likelihood estimate for the average quasar accretion disk size of r_s=4.5^{+1.5}_{-1.2} lt-day at a rest frame wavelength of λ = 1026 Å for microlenses with a mean mass of M = 1 M ☉, in agreement with previous results, and larger than expected from thin disk theory.
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Relativistic and Theoretical Astrophysics
Introduction Gravitational lenses are a powerful tool for Astrophysics and Cosmology. The goals of this project are: i) to obtain a robust determination of the Hubble constant from the time delay measured between the images of a lensed quasar; ii) to study the individual and statistical properties of dark matter condensations in lens galaxies from
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Mediavilla Gradolph