Fermi bubbles: Galactic centre star formation writ large

Abstract

The enormous ∼GeV γray emitting structures recently discovered in Fermi- LAT data and labelled the 'Fermi Bubbles' are, given their north-symmetry around the Galactic plane and the fact that they are emerge from the Galactic centre (GC), are related to the high-energy activity in the Milky Way nucleus. Here I show that these structures are likely related to the sustained, long-duration star-formation processes that have occurred in the GC since the youth of the Galaxy. In particular, our independent modelling of the inner ∼200 pc of the Galaxy - directed at explaining the diffuse, broad-band (radio continuum to TeV γray), non-thermal signal detected from this region - demonstrates that a super-wind type outflow from the GC advects ∼ 1039 erg/s in cosmic ray protons into the Galactic halo, precisely enough to energise the -ray emission from the Fermi Bubbles.