LensMEM: A Gravitational Lens Inversion Algorithm Using the Maximum Entropy Method

Abstract

We present a new algorithm for inverting poorly resolved gravitational lens systems using the maximum entropy method. We test the method with simulations and then apply it to an 8 CHz VLA map of the radio ring lens MG 1654+134. We model the lens as a singular isothermal sphere embedded in an external shear held and find that the critical radius of the lens is b = 0 ''.9820, the dimensionless shear is gamma = 0.0771, and the position angle of the shear is theta = 100 degrees.8. These results are consistent with the results obtained by Kochanek using a complementary inversion algorithm based on Clean.