2000ApJ...534L..71T

We present new results on the recently discovered 69 ms X-ray pulsar AXS J161730-505505, the sixth youngest example of a rotation-powered pulsar. We have undertaken a comprehensive X-ray-observing campaign of AXS J161730-505505 with the ASCA, BeppoSAX, and RXTE observatories and follow its long-term spin-down history between 1989 and 1999 using these observations and archival Ginga and ASCA data sets. The spin-down is not simply described by a linear function as originally thought, but instead we find evidence of a giant glitch (ΔP/P≳10^–6) between 1993 August and 1997 September, perhaps the largest yet observed from a young pulsar. The glitch is well described by steps in P and P{dot} accompanied by a persistent P{ddot} similar to those seen in the Vela pulsar. The pulse profile of AXS J161730-505505 presents a single asymmetric peak that is maintained over all observation epochs. The energy spectrum is also steady over time, characterized by a highly absorbed power law with a photon index Γ=1.4±0.2, consistent with that found for other young rotation powered pulsars.