X-ray Microlensing in RXJ1131-1231 and HE1104-1805

Understand

We present results from a monitoring campaign performed with the Chandra X-ray Observatory of the gravitationally lensed quasars RX J1131-1231 and HE 1104-1805.

• We detect significant X-ray variability in all images of both quasars.
• The flux variability detected in image A of RX J1131-1231 is of particular interest because of its high amplitude (a factor of ~ 20).
• We interpret it as arising from microlensing since the variability is uncorrelated with that of the other images and the X-ray flux ratios show larger changes than the optical as we would expect for microlensing of the more compact X-ray emission regions.