Fermi Large Area Telescope observations of the Vela-X Pulsar Wind Nebula

Understand

We report on gamma-ray observations in the off-pulse window of the Vela pulsar PSR B0833-45, using 11 months of survey data from the Fermi Large Area Telescope (LAT).

• This pulsar is located in the 8 degree diameter Vela supernova remnant, which contains several regions of non-thermal emission detected in the radio, X-ray and gamma-ray bands.
• The gamma-ray emission detected by the LAT lies within one of these regions, the 2*3 degrees area south of the pulsar known as Vela-X.
• The LAT flux is signicantly spatially extended with a best-fit radius of 0.88 +/- 0.12 degrees for an assumed radially symmetric uniform disk.