Polarimetric signatures of hot spots in black hole accretion flows

The flaring events observed in the Sagittarius A* supermassive black hole system can be attributed to non-homogeneous nature of near-horizon accretion flow. Bright regions this flow may associated with density or temperature anisotropies, so-called "bright spot" "hot spots". Such orbiting features explain observations at infrared wavelengths as well recent findings millimeter wavelengths. In work, we study emission from an equatorial bright spot, imposed on a radiatively inefficient background, find polarimetric indicative underlying magnetic field structure and other variables including inclination angle, spot size, spin, more. Specifically, investigate impact these parameters Stokes Q-U signatures that commonly exhibit typical double loop (pretzel-like) structure. Our semi-analytical model, describing plasma conditions is built within framework numerical radiative transfer code ipole, which calculates synchroton 230 GHz. We showcase wide variety relation between inner outer loops. For vertical topology, explained by suppression synchrotron seen distant observer. radial toroidal topologies, \quloop corresponds part orbit where it receding respect Based our models conclude possible constrain topology analysis geometry, particularly combination circular polarization measurements.