X-ray and radio timing of the pulsar in 3C 58

Abstract

We present timing data spanning 6.4 yr for the young and energetic PSR J0205+6449, in the supernova remnant 3C 58. Data were obtained with the Rossi X-ray Timing Explorer, the Jodrell Bank Observatory, and the Robert C. Byrd Green Bank Telescope. We present phase-coherent timing analyses showing timing noise and two spin-up glitches with fractional frequency increases of ∼3.4 × 10-7 near MJD 52555 and ∼3.8 × 10-6 between MJDs 52777 and 53062. These glitches are unusually large if the pulsar was created in the historical supernova in 1181, as has been suggested. For the X-ray timing, we developed a new unbinned maximum likelihood method for determining pulse arrival times, which performs significantly better than the traditional binned techniques. In addition, we present an X-ray pulse profile analysis of four years of RXTE data showing that the pulsar is detected up to ∼40 keV. We also present the first measurement of the phase offset between the radio and X-ray pulse for this source, showing that the radio pulse leads the X-ray pulse by φ = 0.10 0.01 in phase. We compile all known measurements of the phase offsets between radio and X-ray and radio and γ-ray pulses for X-ray and γ-ray pulsars. We show that there is no relationship between pulse period and phase offset, supported by our measurement of the phase offset for PSR J0205+6449. © 2009. The American Astronomical Society. All rights reserved.