The Radio to GeV Afterglow of GRB 221009A

Understand

GRB 221009A ($z=0.151$) is one of the closest known long $\gamma$-ray bursts (GRBs).

• Its extreme brightness across all electromagnetic wavelengths provides an unprecedented opportunity to study a member of this still-mysterious class of transients in exquisite detail.
• We present multi-wavelength observations of this extraordinary event, spanning 15 orders of magnitude in photon energy from radio to $\gamma$-rays.
• We find that the data can be partially explained by a forward shock (FS) from a highly-collimated relativistic jet interacting with a low-density wind-like medium.