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Title: The average size and temperature profile of quasar accretion disks

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 (r{sub s} ∝λ {sup p}, corresponding to a disk temperature profile of T∝r {sup –1/p}) of p=0.75{sub −0.2}{sup +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{sub s}=4.5{sub −1.2}{sup +1.5} lt-day at a rest frame wavelength of λ = 1026 Å for microlenses with a mean mass of M = 1 M {sub ☉}, in agreement with previous results, and larger than expected from thin disk theory.
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ;  [6]
  1. Departamento de Física Teórica y del Cosmos. Universidad de Granada, Campus de Fuentenueva, E-18071 Granada (Spain)
  2. Instituto de Astrofísica de Canarias, Vía Láctea S/N, La Laguna E-38200 Tenerife (Spain)
  3. Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
  4. Departamento de Astronomía y Astrofísica, Universidad de Valencia, E-46100 Burjassot, Valencia (Spain)
  5. Departamento de Física y Astronomía, Universidad de Valparaíso, Avda. Gran Bretaña 1111, Playa Ancha, Valparaíso 2360102 (Chile)
  6. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
Publication Date:
OSTI Identifier:
22351349
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 783; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; EMISSION; FORECASTING; GRAVITATIONAL LENSES; IMAGES; MASS; PHOTOMETRY; QUASARS; SCALING; SPECTROSCOPY; WAVELENGTHS