Advection-Dominated Accretion Model for Sagittarius A${}^{\ast }$: Evidence for a $10^6\msun$ Black Hole at the Galactic Center

Ramesh Narayan, Insu Yi, Rohan Mahadevan

The enigmatic radio source Sagittarius A* at the centre of our Galaxy appears to be a low-luminosity version of active galactic nuclei in other galaxies. By analogy with active gal…