Treffer: Black Hole Imaging: Tackling the SgrA* orbital motion riddle

On 22, 28 July 2018, the GRAVITY instrument of the European Southern Observatory - Very Large Telescope captured the orbital motion of two unique emission sources around the supermassive black hole located at the center of the Milky Way. These flaring events traversed a distance of $\sim 120\,\mu\text{as}$ over a duration of $\sim 30\,\text{min}$, tracing a significant part of a circular orbit in the vicinity of the black hole. To our great surprise, their maximum brightness reached the brightness value of the star S2, which is approximately equal to $\sim15\,\text{mJy}$. Exploring the motion of these flares remains an open problem in the scientific community and has been the driving force behind this work. In the course of our research, we developed a new General Relativistic Radiative Transfer code in Python that simultaneously solves the geodesic equations of motion and the radiative transfer equations for light. The result is a complete visualization of the spacetime around a black hole, yielding both the trajectories and the intensity of the radiation. In this work, we present the fundamental elements of the code, validate our results against existing literature, and attempt to interpret the observational data from GRAVITY regarding the motion of bright sources in black-hole environments.