The X-ray view of the central degrees of the Milky Way

Séminaire IPAG de Gabriele Ponti (MPE, Garching), jeudi 5 novembre 2015 à 11h00, IPAG seminar room

The Milky Way centre hosts a supermassive Black Hole (BH) with a mass of ∼4×106M⊙. Sgr A∗, its electromagnetic counterpart, currently appears as an extremely weak source with a luminosity L∼10^-9 LEdd, occasionally showing flares lasting up to few hours. I will present evidence for an increase of the flaring activity and I will discuss the association of this behaviour with the peri-center passage of the G2 dusty object. In addition, I will give an overview of the past activity of Sgr A*, showing that the supermassive BH was brighter ( 10^6 times) a few hundreds years ago. Finally, I will present the deepest XMM–Newton mosaic map of the central 1.5 deg of the Galaxy, which allowed us to discover new features (such as supernova remnants, superbubbles), to estimate the star formation rate in the region, and to detect warm plasma at high Galactic latitude. This might be associated with an inhomogeneous hot ‘atmosphere’ over the GC, perhaps fed by continuous or episodic outflows of mass and energy from the GC region.