From Pulsar Spin to Pulsar Wind: The Spectral Connection?

We present preliminary results from a systematic spectral study of pulsars and their wind nebulae using the Chandra X-Ray Observatory. The superb spatial resolution of Chandra allows us to differentiate the compact object’s spectrum from that of its surrounding nebulae. Specifically, for six Crab-like pulsars, we compare spectral fits of the averaged pulsar wind nebulae (PWN) emission to that of the central core using an absorbed power-law model. These results suggest an empirical relationship between the bulk averaged photon indices for the PWNe and the pulsar cores; ΓPWN = 0.8 × ΓCore + 0.8. The photon indices of PWNe are found to fall in the range of 1.3 < ΓPWN < 2.3. We propose that the morphological and spectral characteristics of the pulsars observed herein seem to indicate consistent emission mechanisms common to all young pulsars. We point out that the previous spectral results obtained for most X-ray pulsars are likely contaminated by PWN emission.