Abstract
High energy γ-rays from individual giant molecular clouds contain unique information about the hidden sites of acceleration of galactic cosmic rays, and provide a feasible method for study of propagation of cosmic rays in the galactic disk on scales ≤100 pc. I discuss the spectral features of π0-decay γ-radiation from clouds/targets located in proximity of relatively young proton accelerators, and speculate that such `accelerator+target’ systems in our Galaxy can be responsible for a subset of unidentified EGRET sources. Also, I argue that the recent observations of high energy γ-rays from the Orion complex contain evidence that the level of the `sea’ of galactic cosmic rays may differ significantly from the flux and the spectrum of local (directly detected) particles.
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Aharonian, F. Gamma Rays From Molecular Clouds. Space Science Reviews 99, 187–196 (2001). https://doi.org/10.1023/A:1013845015364
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DOI: https://doi.org/10.1023/A:1013845015364