2006ApJ...652.1531M

We report on more than 7 yr of monitoring of PSR J0537-6910, the 16 ms pulsar in the LMC, using data acquired with RXTE. During this campaign the pulsar experienced 23 sudden increases in frequency (``glitches'') amounting to a total gain of over 6 ppm of rotation frequency superposed on its gradual spin-down of ν{dot}=-2x10^–10 Hz/s. The time interval from one glitch to the next obeys a strong linear correlation to the amplitude of the first glitch, with a mean slope of about 400 days/ppm (6.5 days µ/Hz), such that these intervals can be predicted to within a few days, an accuracy that has never before been seen in any other pulsar. There appears to be an upper limit of ∼40 µHz for the size of glitches in all pulsars, with the 1999 April glitch of PSR J0537-6910 the largest so far. The change of its spin-down across the glitches, Δν{dot}, appears to have the same hard lower limit, -1.5x10^–13 Hz/s, as that observed in all other pulsars. The spin-down continues to increase in the long term, ν{ddot}=-10^–21 Hz/s2, and thus the timing age of PSR J0537-6910 (-0.5νν{dot}^–1) continues to decrease at a rate of nearly 1 yr every year, consistent with movement of its magnetic moment away from its rotational axis by 1 rad every 10,000 yr, or about 1 m/yr. PSR J0537-6910 was likely to have been born as a nearly aligned rotator spinning at 75-80 Hz, with a|ν{dot}| considerably smaller than its current value of 2x10^–10 Hz/s. Its pulse profile consists of a single pulse that is found to be flat at its peak for at least 0.02 cycles.