Cosmic rays are important probe of a number of fundamental physical problems such as the acceleration of high and very high energy particles in extreme astrophysical environments. The Galactic center is widely anticipated to be an important cosmic-ray source and the observations of some Imaging Atmospheric Cherenkov Telescopes did successfully reveal a component of TeV-PeV cosmic rays in the vicinity of the Galactic center. Here we report the identification of GeV-TeV cosmic rays in the central molecular zone with the γ-ray observations of the Fermi Large Area Telescope, whose spectrum and spatial gradient are consistent with that measured by the Imaging Atmospheric Cherenkov Telescopes but the corresponding cosmic-ray energy density is substantially lower than the so-called cosmic-ray sea component, suggesting the presence of a high energy particle accelerator at the Galactic center and the existence of a barrier that can effectively suppress the penetration of the particles from the cosmic-ray sea to the central molecular zone.
Dr. Xiaoyuan Huang obtained his PhD from the National Astronomical Observatories, Chinese Academy of Sciences in 2013. Later he moved to Nanjing to work as a postdoc in the DAMPE collaboration. He then moved to the Technical University of Munich supported by the Humboldt Research Fellowship and moved to the Niels Bohr Institute as a postdoc. Since 2020, he is a faculty at the Purple Mountain Observatory. His main research topics are the dark matter indirect detection and high energy astrophysics.