Special Session SS35  1 July 2024

Galactic PeVatrons: searching for the most powerful particle accelerators in the Milky Way

Aims and scope

Since their discovery over a hundred years ago cosmic rays remain the fundamental topic of high-energy astrophysics, acting as one of the main orienteers in shaping strategies for multi-wavelength and multi-messenger observation missions. Cosmic rays with energies up to the knee feature in the spectrum, a spectral break at a couple of PeV, are considered to be produced in our Galaxy. However, the locations at which acceleration of particles up to PeV energies takes place within our Galaxy remains one of the key open questions in the field. A long-standing paradigm constitutes that Galactic cosmic rays are produced mainly in supernova remnants, but there is growing evidence (both observational and theoretical) that typical supernova remnants are not capable of accelerating particles all the way up to the knee. The improvement of numerical simulations that are providing increasingly detailed descriptions of the acceleration process together with the remarkable development of observational astronomy in recent years re-ignited the discussions on potential sources of PeV cosmic rays in our Galaxy. Recent discoveries (notably from the LHAASO experiment) of the gamma-ray emission at multi-PeV energies from a number of sources as well as the IceCube discovery of diffuse neutrinos from the Galactic plane that require multi-PeV protons added important pieces of information to the global picture. In this special session we would like to bring together the experts from both theoretical and experimental sides to review and discuss the current status of the field in an attempt to tackle the puzzle of identifying the PeVatrons, factories of PeV particles, in our Galaxy. The understanding of the progenitors and populations or potential cosmic-ray sources requires a strong synergy between observations and expertise in different wavebands. While the link between the cosmic-ray community and the gamma-ray community is strong, more exchanges with the optical, radio and X-ray communities are needed and will be encouraged in the framework of this special session.


  • Effective particle acceleration at astrophysical shocks
  • Supernova remnants: necessary conditions to reach PeV energies
  • Pulsar wind nebulae as leptonic accelerators
  • Alternative PeVatron candidates: stellar clusters, microquasars, Galactic centre, etc.
  • Diffuse cosmic rays and neutrinos from the Galactic plane
  • Multiwavelength observations of Galactic PeVatrons

Invited speakers

  • Laura Olivera-Nieto (Max-Planck-Institut für Kernphysik, Heidelberg, Germany): Observations of Galactic PeVatrons: current status and future prospects
  • Thibault Vieu (Max-Planck-Institut für Kernphysik, Heidelberg, Germany): Candidate acceleration scenarios for Galactic PeVatrons

Scientific organisers

  • Iurii Sushch (GSSI, L'Aquila, Italy/North-West University, South Africa/Ivan Franko National University of Lviv, Ukraine) - Chair
  • Robert Brose (Dublin City University/Dublin Institute for Advanced Studies, Ireland) - Co-Chair
  • Emma de Oña Wilhelmi (DESY Zeuthen, Germany)
  • Alison Mitchell (Erlangen Centre for Astroparticle Physics, FAU Erlangen-Nürnberg, Germany)
  • Brian Reville (Max-Planck-Institut für Kernphysik, Heidelberg, Germany)
  • Justine Devin (Laboratoire Univers et Particules de Montpellier, CNRS/IN2P3, France)
  • Barbara Olmi (INAF - Osservatorio Astrofisico di Arcetri, Firenze, Italy)
  • Aya Bamba (The University of Tokyo, Japan)
  • Pierre Cristofari (Observatoire de Paris, France)
  • Ke Fang (University of Wisconsin, Madison, USA)
    • Contact

      iurii.sushch @ gmail.com, broserob @ cp.dias.ie

      Updated on Fri Jan 19 11:24:30 CET 2024