X-ray emission from the 63 ms radio pulsar PSR J1105-6107

We have detected significant X-ray emission from the direction of the young radio pulsar PSR J1105-6107 using the ASCA Observatory. The emission shows no evidence of pulsations; the pulsed fraction is less than 31%, at the 90% confidence level. The X-ray emission can be characterized by a power-law spectrum with photon index α = 1.8 ± 0.4, for a neutral hydrogen column density NH = 7 x 1021 cm-2. The unabsorbed 2 - 10 keV flux assuming the power-law model is (6.4 ± 0.8) x 10-13 ergs cm-2 s-1. The implied efficiency for conversion of spin-down luminosity to ASCA-band emission is (1.6 ± 0.2) x 10-3, assuming a distance of 7 kpc to the source. We argue that the X-rays are best explained as originating from a pulsar-powered synchrotron nebula