NPA Seminar: Felix Aharonian, Max Planck Institute, "Gamma-rays and antiparticles in galactic cosmic rays"

Tuesday Mar 5, 2019, 1:00 PM → 3:00 PM US/Eastern

WL 216

The anomalously high fluxes of positrons and antiprotons found in cosmic rays can be satisfactorily explained by introducing two new elements to the current "standard" paradigm of Galactic CRs, namely assuming that  (1) antiparticles are produced in interactions of primary CRs not only in the interstellar medium but also inside the accelerators, (2) CRs are contributed by two different source populations with soft and  hard energy distributions.  The superposition of contributions of two source populations also explains the reported hardening of the spectra of CR protons and nuclei above 200 GeV/amu. The 2nd source population accelerating CRs with a rate at the level below 10 percent of the power of the 1st source population, may consist of Pevatrons responsible for the highest energy particles in galactic CRs up to the “knee” around 10^15 eV.  I will argue that while the 1st population of accelerators most likely consists of Supernova Remnants,  the clusters of young massive stars are plausible candidates for Galactic Pevatrons.

Aharonian-npa-poster-03052019.pdf