Giant molecular clouds emit ultrahigh-energy gamma rays, telescope reveals

AI Insight

The LHAASO (Large High Altitude Air Shower Observatory) has detected ultrahigh-energy gamma rays with energies exceeding 100 TeV emanating from giant molecular clouds in our galaxy. These gamma rays are produced when cosmic rays interact with the dense gas in these clouds, providing direct evidence that molecular clouds act as natural particle detectors revealing the presence of PeV-scale cosmic rays (PeVatrons). The observations identify multiple sources and demonstrate that cosmic rays are accelerated to petaelectronvolt energies within our galaxy.

Why it matters

This discovery helps solve the century-old mystery of cosmic ray origins by confirming that our galaxy contains sources capable of accelerating particles to extreme energies. Understanding cosmic ray acceleration mechanisms has implications for astrophysics, particle physics, and our understanding of high-energy processes throughout the universe.