Modelling anomalous lensed quasars

Abstract

Several gravitationally lensed quasars are observed with anomalous magnifications in pairs of images that straddle a critical curve. Simple theoretical arguments suggest that the magnification of these images should be approximately equivalent, whereas one image is observed to be significantly demagnified. Microlensing offers a possible explanation for this discrepancy. I will discuss the significance of the two key parameters in modelling this effect: the fraction of smooth matter in the lens at the image positions, and the size of the quasar emission region. We have applied our model to the anomalous lensed quasar MG 0414+0534, and found a 95 percent upper limit of 2.62 × 1016cm on the radius of the I-band emission region. The smooth matter percentage in this lens is unconstrained. Show more