# Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope - Astrophysics > High Energy Astrophysical Phenomena

Abstract: Radio pulsar PSR J1028-5819 was recently discovered in a high-frequencysearch at 3.1 GHzin the error circle of the EGRET source 3EG J1027-5817.
Thespin-down power of this young pulsar is great enough to make it very likely thecounterpart for the EGRET source.
We report here the discovery of gamma-raypulsations from PSR J1028-5819 in early observations by the Large AreaTelescope LAT on the Fermi Gamma-Ray Space Telescope.
The gamma-ray lightcurve shows two sharp peaks having phase separation of 0.460 +- 0.004, trailingthe very narrow radio pulse by 0.200 +- 0.003 in phase, very similar to that ofother known $\gamma$-ray pulsars.
The measured gamma-ray flux gives anefficiency for the pulsar of 10-20% for outer magnetosphere beam models.
Noevidence of a surrounding pulsar wind nebula is seen in the current Fermi databut limits on associated emission are weak because the source lies in a crowdedregion with high background emission.
However, the improved angular resolutionafforded by the LAT enables the disentanglement of the previous COS-B and EGRETsource detections into at least two distinct sources, one of which is nowidentified as PSR J1028-5819.

Author: The Fermi-LAT Collaboration

Source: https://arxiv.org/