19-21 February 2019
"Sapienza" University, Phys. Dept. Marconi
Europe/Rome timezone

Relativistic effects in stellar orbits and gas around the Galactic Center black hole

21 Feb 2019, 11:56
Aula Amaldi ("Sapienza" University, Phys. Dept. Marconi)

Aula Amaldi

"Sapienza" University, Phys. Dept. Marconi

talk Gravity: Experiments General Relativity & Cosmology


Odele Straub (Max Planck Institute for Extraterrestrial Physics)


The supermassive black hole in the center of our galaxy is the closest of its kind and the largest in the sky. It is surrounded by a small cluster of high velocity stars called S-stars. Their trajectories are governed by the gravitational field of the black hole. We used the Very Large Telescope (VLT) instruments GRAVITY and SINFONI to follow the star S2/S-02 during its pericenter passage, collecting astrometric and spectroscopic data, respectively. These joint data allow a now robust detection of the combined gravitational redshift and transverse Doppler effect for S2/S-02. During high emission states (bright flares), GRAVITY also recorded continuous changes in position and polarisation of the IR source Sgr A* itself. These are attributed to a compact source of synchrotron emission (hot spot) from the innermost stable circular orbit around the black hole. I will discuss how we obtained our recent result and what it means in the context of gravity theories.

Primary author

Odele Straub (Max Planck Institute for Extraterrestrial Physics)

Presentation Materials