Tootfinder

Characterization of downward Terrestrial Gamma-ray Flashes detected at the Pierre Auger Observatory
Roberta Colalillo (for the Pierre Auger Collaboration), Joseph Dwyer, John Ortberg, David M Smith
https://arxiv.org/abs/2507.15669

Characterization of downward Terrestrial Gamma-ray Flashes detected at the Pierre Auger Observatory
Downward Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond bursts of MeV gamma rays produced in thunderclouds. According to the Relativistic Runaway Electron Avalanche model, gamma rays are produced, via bremsstrahlung, from electron cascades activated by a relativistic "seed" electron. It is not clear what mechanism is responsible for the acceleration of electrons to relativistic energies in electric discharges. To better understand the acceleration sites and the TGF production mechanis…