Abstract
Recently evidence has emerged for enormous features in the -ray sky observed by the Fermi-LAT instrument: bilateral ”bubbles” of emission centered on the core of the Galaxy and extending to around 10 kpc from the Galactic plane. These structures are coincident with a nonthermal microwave ”haze” and an extended region of x-ray emission. The bubbles’ -ray emission is characterized by a hard and relatively uniform spectrum, relatively uniform intensity, and an overall luminosity , around 1 order of magnitude larger than their microwave luminosity while more than order of magnitude less than their x-ray luminosity. Here we show that the bubbles are naturally explained as due to a population of relic cosmic ray protons and heavier ions injected by processes associated with extremely long time scale ( 8 Gyr) and high areal density star formation in the Galactic center.
- Received 19 October 2010
DOI:https://doi.org/10.1103/PhysRevLett.106.101102
© 2011 American Physical Society