Probing black hole shadows

Abstract

General Relativity(GR) is the theory of gravity that better describes how objects fall under the presence of strong gravitational fields. Describing body’s trajectories in the presence of compact object, predicting gravity waves, and in particular, the existence of black holes. The observations made by the Event Horizon Telescope(EHT), about the black holes in the centre of the galaxy M87, and in centre of the Milk Way, Sgr A*, gave rise to a new era in testing black hole theory and GR itself by means of luminosity coming from electromagnetic radiation of the accretion disk. Theoretical analysis and General Relativistic Magnetohydrodynamics(GRMHD) universally agree on two facts: The existence of a photon ring, and a luminosity gradient descent caused by the light rays emiited by the accretion disk that intersect the event horizon(EH), and thus, don’t ever get to the detector. Hence, forming a shadow. This undergraduate thesis aims to review because of the very few available test within GR, specially for black holes, it becomes extremely necessary the use of ’Shadowgraphy’, e.g, have some better observational viability in astrophysical scenarios, through numerical simulations for light ray geodesics, i.e, the ray tracing protocol, as well as simulating the properties of the accretion disk by the intensity profile distribution functions, so that one can extract optical, geometrical and emission information of the accretion disk.