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Session 16 - Radio Pulsars.
Display session, Monday, January 15
North Banquet Hall, Convention Center
An investigation of timing noise in the Crab pulsar is conducted using high quality radio timing covering the period 1982-1989. Removal of a polynomial trend from the arrival time data reveals a "quasiperiodic" appearing residual. Previous analysis on earlier data have shown that such residuals can arise simply from detrending a red power-law noise process. These earlier analysis assumed that red power-law noise was restricted to even integer power-law indices (which arise from successive integrals of white noise) and concluded that the Crab pulsar timing noise was consistent with 1/f^4 noise. We present a general time-domain method of creating red power-law noise samples with an arbitrary power-law index. A power spectral analysis is performed on the Crab pulsar timing residual using a window function to limit the severe power "leakage" that occurs with very red processes. The same analysis is conducted on simulated data showing that the power-law index can be correctly recovered. The power spectrum of the Crab pulsar timing noise reveals two components: a 1/f^3 power-law noise process and a superposed large amplitude quasiperiodic process with a period of approximately 550 days. The quasiperiodic feature in the power-spectrum is shown to be highly significant and not an aritfact of detrending power-law noise.
Program listing for Monday