Analytical techniques for polarimetric imaging of accretion flows in the Schwarzschild metric

Emission from an accretion disk around compact objects, such as neutron stars and black holes, is expected to be significantly polarized. The polarization can used put constraints on the geometrical physical parameters of sources – their radii, masses, spins well determine orbital parameters. radiation escaping innermost parts strongly affected by gravitational field object relativistic velocities matter. straightforward calculation observed signatures involves a computationally expensive ray-tracing technique. At same time, having fast computational routines for direct data fitting becoming increasingly important in light currently images flow supermassive hole M 87 Event Horizon Telescope infrared coming Sgr A*, upcoming X-ray measurements Imaging Polarimetry Explorer enhanced Timing mission. In this work, we obtain exact analytical expression rotation angle plane Schwarzschild metric accounting effects bending aberration. We show that flux, degree, function energy performed analytically with high level accuracy using approximate light-bending formula, eliminating need precomputed tabular models routines.