Multiple Sources of Solar High-energy Protons

Where do the remarkable long-duration flare gamma rays, so nicely observed by Fermi/LAT, actually come from? This cartoon shows "all possible" sources, the authors assert, but that is a bit puzzling since several papers try to associated these high-energy gamma rays with SEPs accelerated at the bow shock. These could certainly precipitate outside the flaring (red) region, in principle.

This interesting subject has hardly been touched in the Archive here, although the Bespalov cartoon touches on the physics. The obverse of the problem, namely the "escape" of particles into the heliosphere, has attracted much more attention.