A search for the radio counterpart of the unidentified γ-ray source 3EG J1410-6147

Abstract

We have made radio continuum, Hi and X-ray observations in the direction of the unidentified EGRET source 3EG J1410-6147, using the Australia Telescope Compact Array and the Chandra X-ray Observatory. The observations encompass the supernova remnant (SNR) G312.4-0.4 and the two young pulsars PSRs J1412-6145 and J1413-6141. We derive a lower distance limit of 6 kpc to the SNR, although interpretation of positive velocity features in the Hi spectrum may imply that the SNR is more distant than 14 kpc. PSR J1412-6145, with an age of 50 kyr, is the pulsar most probably associated with SNR G312.4-0.4. X-rays are not detected from either pulsar and diffuse X-ray emission near the bright western edge of the SNR is weak. Although there is circumstantial evidence that this western region is a pulsar wind nebula (PWN), the embedded pulsar PSR J1412-6145 is apparently not sufficiently powerful to explain the radio enhancement. The origin of the electron acceleration in this region and of the γ-rays remains unidentified, unless the distance to PSR J1413-6141 is at least a factor of 3 lower than its dispersion measure distance.