Sera Markoff (University of Amsterdam, Netherlands) - Jeudi 6 février.
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), so 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 agree with sophisticated general relativistic magnetohydrodynamical simulations. These results provide a baseline for new progress on several major questions regarding the launching of relativistic jets, the acceleration of particles within these jets, spin and strong gravity effects. I will present some recent examples of how Sgr A* is elucidating key physics relevant for black holes of all mass scales, and how we are beginning to understand its relation to more typical sources.
You can also watch this video on the multimedia site ENS :savoirs.ens.fr