Publication date: Dec 2017
Abstract:
In this work we present investigation of the escape cones of null-
geodesics from the interior of rotating homogeneous compact stars in the
model, where only terms linear in the star’s rotational frequency are
assumed. We focus on the single model of the star with particular radius
R = 2.8M (using units in which c = G = 1) rotating with different values
of angular momentum J. We vary the position of the isotropically
radiating source both in radial and latitudinal direction and we show
the impact of the position and the rotational rate on the shape of the
escape cone of null-geodesics. We find that even for small rotational
rate corresponding to j = J/M2 = 0.1 the impact on the escape cones is
rather strong. The escape cones are no longer symmetrical around radial
direction, and it is clearly seen that the radiation in the direction of
the rotation can easily reach the infinity. On the other hand, the
radiation in the direction opposite to the rotation will be trapped in
the interior of the star. We discuss possible astrophysical relevance of
our results.
Authors:
Vrba, Jaroslav; Urbanec, Martin; Stuchlík, Zdeněk;