Search for GeV-TeV emission from GRB 080319B using the Milagro Observatory

On March 19, 2008 NASA’s Swift satellite discovered one of the brightest gamma-ray bursts ever recorded. With a peak visual magnitude of 5.3, GRB 080319B was dubbed the “naked-eye” gammaray burst, as an observer under dark skies could have seen the burst without the aid of an instrument. Due to the proximity in both time and space to GRB 080319A, prompt emission from GRB 080319B was detected in both the optical and γ-ray bands by several wide-field instruments. Follow-up observations spanned 11.5 orders of magnitude in wavelength, making GRB 080319B one of the most wellstudied gamma-ray bursts to date. The Milagro observatory was an extended air shower array located near Los Alamos, NM, that operated from January 2000 to May 2008. GRB 080319B was fortuitously located in the field of view of Milagro, and a search for prompt emission in the GeV-TeV energy range is presented here. No evidence for emission is found and constraining upper limits on VHE emission from GRB 080319B are obtained.