Speaker
Description
Recent discoveries of diffuse gamma rays and neutrinos from Galactic plane provide strong evidence of Galactic PeVatrons, but what kind of astrophysical objects are accelerating PeV cosmic rays are still unknown. In addition, LHAASO has identified mysterious "dark" sources with no clear counterparts at lower gamma-ray energies, posing a new astrophysical puzzle. In this talk, I will introduce isolated black holes wandering in molecular clouds as the sources of LHAASO dark sources and PeV cosmic rays observed on Earth. Isolated black holes in molecular clouds accretes surrounding dense gas, and magnetized accretion flows can accelerate cosmic rays up to PeV energies. These PeV cosmic rays escape from the accretion flows and interact with ambient molecular gas, producing ultrahigh-energy gamma-rays. Considering the population of isolated black holes in our Galaxy, they can energetically explain PeV cosmic-rays observed on Earth.
