The Milky Way – evidence for Seyfert activity in the recent past (speaker: Joss Bland-Hawthorn, University of Sydney and Sydney Institute for Astronomy)

Date: 
Tuesday, November 17, 4:00pm
Location: 
Marlar Lounge (37-252)

Abstract: 
The Galaxy's supermassive black hole is a hundred times closer than any other massive singularity. It is surrounded by a highly unstable gas disk so why is the black hole so peaceful at the present time? This mystery has led to a flurry of models in order to explain why Sgr A* is radiating far below (1 part in 108) the Eddington accretion limit. But has this always been so? Evidence is gathering that Sgr A* has been far more active in the recent past, on timescales of thousands of years and longer. The bipolar wind discovered by MSX, the gamma-ray bubbles discovered by Fermi-LAT, the WMAP haze, the positronium flash confirmed by INTEGRAL, are suggestive of something truly spectacular in the recent past. We present new evidence that the Galactic Centre was a full blown "active galaxy" just two million years ago. The echo of this incredible event can be seen today imprinted across the Galaxy.

 

Talk Host:  Anna Frebel

Additional information about Joss Bland-Hawthorn