China’s LHAASO maps cosmic ray source three times sun’s size

China’s Large High Altitude Air Shower Observatory (LHAASO) has identified Cygnus X-3 as the most powerful particle accelerator observed to date, exceeding previous theoretical limits for galactic cosmic-ray energies. Researchers confirmed that this binary system accelerates particles to at least 30 PeV, far beyond the approximately 1 PeV previously thought possible within the Milky Way. LHAASO also constrained the acceleration region to just three times the solar radius, revealing a surprisingly compact source for such energetic emissions.

LHAASO Confirms Cygnus X-3 Accelerates Particles to 30 PeV

LHAASO’s recent observations reveal Cygnus X-3 accelerates particles to 30 PeV, exceeding previous expectations for galactic cosmic-ray sources. Mainstream theories previously limited the maximum energy of particles within the Milky Way to approximately 1 PeV.

The binary system, comprised of a compact object and a massive companion star, achieves this acceleration as it draws material from the companion’s stellar wind, a process now understood to be more potent than previously modeled. This finding, originating from the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences (CAS), fundamentally alters the understanding of particle acceleration mechanisms in extreme astronomical environments.

Detailed analysis of gamma-ray emissions allowed researchers to not only confirm the 30 PeV energy level, but also to identify a distinct 4.8-hour periodicity within the ultra-high-energy signal. Cao Zhen, principal investigator of LHAASO and an academician of CAS, detailed the methodology behind the discovery, stating, “Through detailed analysis of the time variability and spectral characteristics of ultra-high-energy gamma rays, LHAASO has confirmed that Cygnus X-3 can accelerate cosmic-ray particles to energies of at least 30 PeV.” The implications of this discovery extend beyond Cygnus X-3 itself; researchers believe it unlocks new avenues for studying extreme physics around black holes and neutron stars.

The remarkably small acceleration zone suggests that magnetic reconnection or other highly efficient processes are at play, demanding a reevaluation of current astrophysical models. Scientists suggest these findings, recently published in National Science Review, will drive further investigation into the behavior of matter under the most intense gravitational and electromagnetic forces in the universe, potentially revealing new insights into the origins of cosmic rays and the fundamental laws governing the cosmos.