Abstract

Sgr A* is the weakest accreting black hole we have ever observed, yet it is not a particularly unique object. We know that the majority of galaxies harbor nuclear black holes more like Sgr A* than bright active galactic nuclei (AGN), thus our Galactic center represents a dominant stage in the “typical” life cycle of a spiral galaxy. I will discuss our current understanding of accretion around Sgr A*, the only source so far where we can directly image near-event horizon scales, and where semi-analytical models are starting to agree with sophisticated general relativistic magnetohydrodynamical simulations. These results provide a baseline for addressing several major questions relevant to the wider impact of black holes in the universe, such as feedback in galaxies and clusters, or high energy particle acceleration. I will present some recent examples of how Sgr A* is elucidating key physics relevant for black holes at all mass scales.