Session: Cosmology and Relativistic Astrophysics
Name: Mr. Ioannis Dimitropoulos (University of Patras)
Coauthors:
No coauthors were included.
Type: Oral
Title: Sgr A* flares, an electromagnetic signal and more
Abstract:
Sagittarius A* is a super massive black hole in the center of our galaxy observed across the
electromagnetic spectrum for decades. Moreover, it is the primary target of the Event Horizon
Telescope (EHT) and the GRAVITY collaboration, which observe in the 230 GHz (EHT) and the
NIR (GRAVITY). The compact radio emission is expected to be thermal radiation from the
vicinity of the black hole. The NIR emission exhibits strong variability and flares which are observed from the Galactic center every 6-8 hours. Flaring activity has been attributed to reconnection events close to the Black hole. We perform general-relativistic magneto-
hydrodynamic to model the accretion flow of SgrA*, and employ thermal emission models to
reproduce the emission at 230 GHz, analyzing the regions close to the black hole that this
emission is generated. Furthermore, we monitor the magnetic re-connection events in the
simulation and model the non-thermal emission at the NIR. Our investigation focuses on the
production of flares from Sgr A* observed in the NIR from GRAVITY, our aim is to reproduce a
model that calculates lightcurves at these frequencies.