The Spatial Structure of an Accretion Disk
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Date
2008-01-20
Journal Title
Journal ISSN
Volume Title
Publisher
American Astronomical Society
Abstract
Based on the microlensing variability of the two-image gravitational lens HE 1104-1805 observed between 0.4 and 8 μm, we have measured the size and wavelength-dependent structure of the quasar accretion disk. Modeled as a power law in temperature, T α R^−β, we measure a B-band (0.13 μm in the rest frame) half-light radius of R_1/2, B = 6.7^+ 6.2_−3.2 × 10^15 cm (68% confidence level) and a logarithmic slope of β = 0.61^+0.21_−0.17 (68% confidence level) for our standard model with a logarithmic prior on the disk size. Both the scale and the slope are consistent with simple thin disk models where β = 3/4 and R_1/2, B = 5.9 × 10^15 cm for a Shakura-Sunyaev disk radiating at the Eddington limit with 10% efficiency. The observed fluxes favor a slightly shallower slope, β = 0.55^+0.03 _−0.02, and a significantly smaller size for β = 3/4.
Description
Keywords
accretion, accretion disks, gravitational lensing, quasars: individual (HE 1104-1805)
Citation
Shawn Poindexter, Nicholas Morgan, and Christopher S. Kochanek, "The Spatial Structure of an Accretion Disk," The Astrophysical Journal 673, no. 1 (2008), doi:10.1086/524190