A model for the structure of the gamma-ray bubbles in Milky Way galaxy.
Cardinali A., Coppi B.
A plasma outflow coming from the center of our Galaxy is assumed to reach a "plowed" nearly stationary magnetic field at characteristic galactic distances. Then a lower hybrid mode is envisioned to be excited by the non-thermal features of the nuclei outflow distribution (beam). This mode can then transfer energy, parallel to the magnetic field to high-velocity electrons which can be held responsible for the observed high-energy radiation emission at large distances from the center of the galaxy defining the edge of each bubble.