Parameter study for hot spot trajectories around SgrA*

¹ Department of Physics, National and Kapodistrian University of Athens, University Campus, GR 15784 Zografos, Greece
² Research Center for Astronomy and Applied Mathematics, Academy of Athens, Soranou Efesiou 4, 115 27 Athens, Greece

Received: 30 April 2024
Accepted: 2 July 2024

Abstract

Context. Intense flaring events in the near-infrared and X-ray wavebands of our Galactic center have been the subject of research for decades. In recent years, the GRAVITY instrument of the Very Large Telescope captured the motion and polarimetric signature of such a flare in close proximity to the supermassive black hole.

Aims. This study aims to investigate a broad parameter space for hot spot motion in the vicinity of SgrA* and reproduce the observed flaring behavior.

Methods. To this end, we have developed a general relativistic radiative transfer code and conducted a parameter study including both planar and ejected hot spot configurations around supermassive black holes.

Results. Super-Keplerian orbital frequencies are favored by circular equatorial, cylindrical and parabolic models, whereas conical hot spot trajectories provide a better fit for orbital frequencies below the Keplerian value. Additionally, a distant observer cannot effectively differentiate between Schwarzschild and Kerr black holes, as well as face-on orbits at different observation angles.