Time-Correlated Structure in Pulsar Spin Fluctuations

ORAL

Abstract

I will present evidence for time-correlated structure in the pulsar spin-rate fluctuations known as timing noise. Such evidence has not been found in previous studies of timing noise power spectra, which have revealed no sign of deviations from rigid body rotation. We use two statistics to measure correlations in the time domain: the auto-correlation function and the lagged distribution function. This analysis indicates that pulse arrival time fluctuations are correlated over a correlation time of $\sim$10 days, beyond which no correlation is observed. We interpret this to be the signature of a damped rotational mode in the star, arising from frictional coupling of the solid crust and liquid interior.

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Authors

  • Steven Price

    Montana State University

  • Bennett Link

    Montana State University

  • Ernest Henley

    Green River College, University of British Columbia, Pacific Northwest National Laboratory, BYU-Idaho Dept. of Physics, University of Washington, Applied Physics Technologies, Inc., Montana State University, Universidade Estadual de Campinas, Southern Oregon University, Oregon State University Department of Physics, Oregon State University Department of Chemistry, National Institute of Standards and Technology Center for Neutron Research, Physics Department, Oregon State University, University of Idaho, University of Wyoming, Department of Physics, Montana State University, University of Portland, Idaho State University, WWU, Advanced Light Source, Lawrence Berkeley National Laboratory, Oregon Center for Optics and Department of Physics, University of Oregon, Lewis and Clark, Queen's University, University of Notre Dame, Idaho National Lab, TRIUMF, RCNP, Japan, University of Guelph, Mexico University, St. Mary's University, University of Montreal, Deep River, Dept. of Physics; Montana State University, Dept. of Plant Sciences and Pathology, Dept. of Chem. and Biochem.; Montana State University, Department of Physics, Shandong University, P. R. China, Department of Physics, University of Idaho, USA, Dept. of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 Canada, University of Calgary