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Title: The optical, ultraviolet, and X-ray structure of the quasar HE 0435–1223

Microlensing has proved an effective probe of the structure of the innermost regions of quasars and an important test of accretion disk models. We present light curves of the lensed quasar HE 0435–1223 in the R band and in the ultraviolet (UV), and consider them together with X-ray light curves in two energy bands that are presented in a companion paper. Using a Bayesian Monte Carlo method, we constrain the size of the accretion disk in the rest-frame near- and far-UV, and constrain for the first time the size of the X-ray emission regions in two X-ray energy bands. The R-band scale size of the accretion disk is about 10{sup 15.23} cm (∼23r{sub g}), slightly smaller than previous estimates, but larger than would be predicted from the quasar flux. In the UV, the source size is weakly constrained, with a strong prior dependence. The UV to R-band size ratio is consistent with the thin disk model prediction, with large error bars. In soft and hard X-rays, the source size is smaller than ∼10{sup 14.8} cm (∼10r{sub g} ) at 95% confidence. We do not find evidence of structure in the X-ray emission region, as the most likely value for themore » ratio of the hard X-ray size to the soft X-ray size is unity. Finally, we find that the most likely value for the mean mass of stars in the lens galaxy is ∼0.3 M{sub ☉}, consistent with other studies.« less
Authors:
;  [1] ; ;  [2] ;  [3]
  1. Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
  2. Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)
  3. Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424 (United States)
Publication Date:
OSTI Identifier:
22365703
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 789; Journal Issue: 2; 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; ERRORS; GALAXIES; GRAVITATIONAL LENSES; HARD X RADIATION; MASS; MONTE CARLO METHOD; QUASARS; SOFT X RADIATION; STARS; ULTRAVIOLET RADIATION; VISIBLE RADIATION