Gravitational radiation from an accreting millisecond pulsar with a magnetically confined mountain

Abstract

The amplitude of the gravitational radiation from an accreting neutron star undergoing polar magnetic burial is calculated. During accretion, the magnetic field of a neutron star is compressed into a narrow belt at the magnetic equator by material spreading equatorward from the polar cap. In turn, the compressed field confines the accreted material in a polar mountain, which is generally misaligned with the rotation axis, producing gravitational waves. The equilibrium hydromagnetic structure of the polar mountain, and its associated mass quadrupole moment, are computed as functions of the accreted mass M a by solving a Grad-Shafranov boundary value problem. The orientation- and polarization-..