Iurii Sushch | Fantastic Pevatrons and where ot find them

Friday 15 Nov 2024, 10:30 → 12:00 Europe/Berlin

SR 05 (Villa)

Cosmic rays with energies up to about 3 PeV that correspond to the 'knee' feature in the observed spectrum are believed to be of Galactic origin. There is however no indisputable evidence, neither observational nor theoretical, that Galactic sources can supply enough protons of these high energies.  A long-standing paradigm constitutes that the bulk of Galactic cosmic rays at least at lower energies are produced in supernova remnants, which is based mainly on the fact that supernova explosions can provide enough energy to explain the energy density of cosmic rays in the Galaxy. But in recent years it becomes more and more evident that protons can reach PeV energies in supernova remnants only in some special and extreme cases. This together with recent discoveries (notably from the LHAASO experiment) of the gamma-ray emission at multi-PeV energies from a number of sources stimulated discussions of plausible alternatives among which compact massive star clusters and microquasars seem to be the most promising candidates. In this talk I will discuss the current status of the search for PeVatrons from the perspective of theory and modeling focusing on capabilities of the supernova remnant paradigm also extending it to the supernovae explosions within compact stellar clusters.