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The 2009 Fermi Symposium

Fermi-LAT Observations of Gamma-ray Transients Near the Galactic Plane

Elizabeth Hays, NASA/GSFC


The Large Area Telescope on the Fermi Gamma-ray Space Telescope provides unprecedented sensitivity for all-sky monitoring of gamma-ray activity. The observatory scans the entire sky every three hours and allows a general search for flaring activity on daily timescales. This search is conducted automatically as part of the ground processing of the data and allows a fast response to transient events, typically less than a day. Most of the outbursts detected are spatially associated with known blazars, but in several cases during the first year of observations, gamma-ray flares occurring near the Galactic plane did not reveal any initially compelling counterparts. This prompted follow-up observations in X-ray, optical, and radio to attempt to identify the origin of the emission and probe the possible existence of a class of transient gamma-ray sources in the Galaxy. We will report on the details of these LAT events and the results of the multiwavelength counterpart se! arches.