A ROBUST DETERMINATION OF THE SIZE OF QUASAR ACCRETION DISKS USING GRAVITATIONAL MICROLENSING
Using microlensing measurements from a sample of 27 image-pairs of 19 lensed quasars we determine a maximum likelihood estimate for the accretion disk size of an average quasar of r_s=4.0^+2.4_-3.1 light days at rest frame <λ>=1736Å for microlenses with a mean mass of =0.3M_. This value, in good agreement with previous results from smaller samples, is roughly a factor of 5 greater than the predictions of the standard thin disk model. The individual size estimates for the 19 quasars in our
... are also in excellent agreement with the results of the joint maximum likelihood analysis.