Hydromagnetic and Gravitomagnetic Crust-Core Coupling in a Precessing Neutron Star

  title={Hydromagnetic and Gravitomagnetic Crust-Core Coupling in a Precessing Neutron Star},
  author={Yuri Levin and Carolina Villarreal D’Angelo},
  journal={The Astrophysical Journal},
We consider two types of mechanical coupling between the crust and the core of a precessing neutron star. First, we find that a hydromagnetic (MHD) coupling between the crust and the core strongly modifies the star's precessional modes when tA 1/2; here tA is the Alfven crossing timescale, and Tspin and Tprec are the star's spin and precession periods, respectively. We argue that in the precessing pulsar PSR B1828-11 the restoring MHD stress prevents a free wobble of the crust relative to the… 
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