Speaker
Prof.
Isabelle Grenier
(AIM, Université Paris Diderot & CEA Saclay)
Description
The gamma radiation spawn by cosmic rays along their interstellar journey has received much attention over the years as an efficient means to trace the evolution of the cosmic-ray flux and spectrum on kiloparsec scales across the Milky Way.
The data are interpreted in the framework of an elementary scenario which involves cosmic-ray production by diffusive shock acceleration in supernova remnants, a nearly black box for their escape from the source, followed by diffusion at large with energy-dependent, but often spatially uniform diffusion properties. The abundance and quality of the Fermi LAT data allow us to test this scenario and we (happily) start to see a few cracks that I will review: detection or not of irradiated clouds near supernova remnants, cocoon of fresh cosmic rays in OB associations, cosmic-ray gradient problems in and out of the Galactic plane.
Primary author
Prof.
Isabelle Grenier
(AIM, Université Paris Diderot & CEA Saclay)
