Multi-wavelength Emission from the Fermi Bubble I. Stochastic acceleration from Background Plasma

Abstract

We analyse processes of electron acceleration in the Fermi Bubbles in order to define parameters and restrictions of the models, which are suggested for the origin of these giant radio and gamma-ray structures. In the case of leptonic origin of the nonthermal radiation from the Bubbles, these electrons should be produced somehow in-situ because of relatively short lifetime of high energy electrons, which lose their energy by synchrotron and inverse Compton processes. It has been suggested that electrons in Bubbles may be accelerated by shocks produced by tidal disruption of star accreting onto the central black hole or a process of re-acceleration of electrons ejected by supernova remnants. These processes will be investigated in subsequent papers. In this paper we focus to study in-situ stochastic (Fermi) acceleration by a hydromagnetic/supersonic turbulence, in which electrons can be directly accelerated from the background plasma. We showed that the acceleration from the background plasma is able to explain the observed fluxes of radio and gamma-ray emission from the Bubbles but the range of permitted parameters of the model is strongly restricted.

29 pages, 7 figures, accepted for publication in ApJ

References in corpus (10)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Global cosmic-ray related luminosity and energy budget of the Milky Way
• The Fermi Bubbles: Giant, Multi-Billion-Year-Old Reservoirs of Galactic Center Cosmic Rays
• Extended Anomalous Foreground Emission in the WMAP 3-Year Data
• Giant Magnetized Outflows from the Centre of the Milky Way
• Markarian 6: shocking the environment of an intermediate Seyfert
• Shocks, Seyferts and the SNR connection: a Chandra observation of the Circinus galaxy
• Diffusive shock acceleration in radiation dominated environments
• In-situ acceleration of subrelativistic electrons in the Coma halo and the halo's influence on the Sunyaev-Zeldovich effect
• Magnetic substructure in the northern Fermi Bubble revealed by polarized WMAP emission

Cited by in corpus (4)

• Simulating the Fermi Bubbles as Forward Shocks Driven by AGN Jets
• Multi-wavelength Emission from the Fermi Bubble III. Stochastic (Fermi) Re-Acceleration of Relativistic Electrons Emitted by SNRs
• Multi-wavelength Emission from the Fermi Bubble II. Secondary Electrons and the Hadronic Model of the Bubble
• On the high-energy protons regular acceleration in the Fermi Bubbles