A supernova remnant associated with the young gamma-ray pulsar PSR1706-44

THE Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory satellite recently detected1 pulsed -radiation from the radio pulsar PSR1706–44; this is only the fourth radio pulsar to be identified as a -ray source. The other three (Vela, the Crab and PSR1509–58) are all associated with supernova remnants (SNRs), whereas very few—perhaps four—of the remaining 500 or so galactic radio pulsars have convincing associations with SNRs2. We have mapped the field around PSR1706 – 44 at 843 MHz with a resolution of 44 arcsec using the Molonglo Observatory Synthesis Telescope, and have identified a shell-type SNR at a distance of about 3 kpc—consistent with the distance deduced for the pulsar. The pulsar is seen as a slightly variable point source, located in an enhanced knot on the arc of the SNR shell