Gravitational collapse, shear-free anisotropic radiating star

Abstract

We here present a new model of a radiating star for a shear-free spherically symmetric anisotropic fluid undergoing radial heat flow collapsing under its own gravity. The interior metric fulfilled all the relevant physical and thermodynamic conditions and matched with Vaidya exterior metric over the boundary. Initially the interior solutions represent a static configuration of perfect fluid which then gradually starts evolving into radiating collapse. We have observed that the model is well behaved for a set of model parameters and there are a number of such sets for which the model is well behaved. The apparent luminosity as observed by the distant observer at rest at infinity and the effective surface temperature are zero in remote past at the instant when the collapse begins and at the stage when collapsing configuration reaches the horizon of the black hole.