The origin of Galactic cosmic rays: insights from gamma rays (and more)
Stefano Gabici (APC, Parigi)
Friday 06/03/2026 @ 11:30, Sala Antonio Sollima (IV piano Battiferro)
Cosmic rays are mostly made of energetic atomic nuclei (mainly protons). They fill the entire Galaxy and reach the Earth as an isotropic flux of particles. While it is firmly established that the bulk of cosmic rays originates within the Galaxy, the way in which these particles are accelerated at their sources, as well as the way in which they are confined in the magnetized and turbulent interstellar medium are still a matter of debate. An impressive amount of data of ever improving quality has been accumulated over a century of direct and indirect observations of cosmic rays. According to the mainstream interpretation of these data, Galactic cosmic ray nuclei are believed to be accelerated at supernova remnant shocks via first order Fermi mechanism and to be then somehow released into the interstellar medium, where they reside for some time before escaping the Galaxy. I will provide a critical review of this standard paradigm putting particular emphasys on the role played by gamma-ray observations in advancing our understanding of the origin of these particles.