Author(s): Abdo A.A., Ackermann M., B. Atwood W., Baldini L., Ballet J., Barbiellini G., G. Baring M., Bastieri D., M. Baughman B., Bechtol K., Bruel P., Cohen-Tanugi J., Dumora D., Farnier C., Fleury P., Giebels B., Grondin M.-H., Guillemot L., Guiriec Sylvain, Knödlseder J., Komin Nukri, Lemoine-Goumard M., Lott B., Nuss E., Parent D., Piron F., Reposeur T., Sanchez D., A. Smith D., Vilchez N.
(Article) Published:
The Astrophysical Journal / The Astrophysical Journal Letters, vol. 695 p.L72-L77 (2009)
Links openAccess full text : 
Ref HAL: in2p3-00377212_v1
Ref Arxiv: 0903.1602
DOI: 10.1088/0004-637X/695/1/L72
Ref. & Cit.: NASA ADS
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35 citations
Abstract:
Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search (at 3.1 GHz)in the error circle of the EGRET source 3EG J1027-5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of gamma-ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The gamma-ray light curve shows two sharp peaks having phase separation of 0.460 +- 0.004, trailing the very narrow radio pulse by 0.200 +- 0.003 in phase, very similar to that of other known $\gamma$-ray pulsars. The measured gamma-ray flux gives an efficiency for the pulsar of 10-20% (for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028-5819.