Imaging AGN using gravitational microlensing
George Chartas (Penn State) , C. S. Kochanek(OSU), X. Dai(OSU), N. Morgan(OSU), G. Garmire(PSU)
Resolving the emission regions of distant quasars is beyond the current capabilities of present-day telescopes. Until the spacial resolution of telescopes improves to reach the level of tens of nano-arcseconds we will have to rely on indirect methods of mapping the emission regions of quasars. One promising method of imaging AGN accretion disks involves microlensing of the continuum and line emission regions that can occur in lensed AGN. We have initiated a multiwavelength monitoring campaign of several microlensing candidates with the main scientific goal of measuring the structure of AGN in the optical and X-ray bands in order to test disk models. We present constraints on the sizes of AGN accretion disks and their hot coronae. These constraints were obtained by monitoring microlensing events in quasars Q1131-1231 and HE1104-1805. X-ray monitoring observations of these quasars were performed with the Chandra X-ray Observatory and B, R and I band observations were made with the Smarts Consortium 1.2m telescope in Chile. Stacking of the Chandra observations has also provided constraints of the properties of two clusters of galaxies in the vicinity of Q1131-1231.