8th HEAD Meeting, 8-11 September, 2004
Session 35 Surveys and the Cosmic X-ray Background
Oral, Saturday, September 11, 2004, 4:00-5:38pm

## [35.02] The Most Sensitive Survey of the TeV Sky

B. L. Dingus (LANL), Milagro Collaboration

Milagro is a unique, large field of view (~ 2 sr), TeV gamma-ray observatory located near Los Alamos, NM operating continuously to survey the Northern Hemisphere sky. Approximately 3 years of Milagro data have been searched for evidence of TeV point sources, and we detect the known sources of Mrk 421 and the Crab nebula and place 95% confidence upper limits of 275 to 600 mCrab (4.8-10.5\times 10-12 cm-2 s-1) above 1 TeV for source declinations between +5 degrees and +70 degrees. We have also searched for extended sources, such as supernova remnants and galaxy clusters, and detect significant TeV gamma-ray emission from the Galactic plane in the direction of the inner Galaxy. The large aperture and duty cycle of Milagro also allow us to uniquely search for prompt TeV emission from gamma-ray bursts. These results emphasize the utility of a large field of view instrument to survey the TeV sky. Milagro has recently been upgraded to improve its sensitivity by a factor of ~ 2 and plans are being made for HAWC, a larger version of Milagro which would be 20 times more sensitive and capable of detecting the Crab nebula in a single transit.

Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.