2nd-order Fermi acceleration as the origin of the Fermi bubbles

Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

4 pages, 5 figures; to appear in Proceedings of the 32nd International Cosmic Ray Conference, Beijing, China, 11-18 August 201

Scientific paper

Gamma-ray data from Fermi-LAT show a bi-lobular structure extending up to 50 degrees above and below the Galactic centre, coincident with a possibly related structure in the ROSAT X-ray map which presumably originated in some energy release close to the centre a few million years ago. It has been argued that the gamma-rays arise due to inverse Compton scattering of relativistic electrons accelerated at plasma shocks present in the bubbles. We explore the alternative possibility that the relativistic electrons undergo stochastic 2nd-order Fermi acceleration in the entire volume of the bubbles by plasma wave turbulence. This turbulence is generated behind the outer shock and propagates into the bubble volume, leading to a non-trivial spatial variation of the electron spectral index. Rather than a constant volume emissivity as predicted in other models we find an almost constant surface brightness in gamma-rays and also reproduce the observed sharp edges of the bubbles. We comment on possible cross-checks in other channels.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

2nd-order Fermi acceleration as the origin of the Fermi bubbles does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with 2nd-order Fermi acceleration as the origin of the Fermi bubbles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 2nd-order Fermi acceleration as the origin of the Fermi bubbles will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-190532

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.