Long-term changes in pulsar periods and the plasma in neutron star interiors

Abstract

view Abstract Citations (21) References (8) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Long-term changes in pulsar periods and the plasma in neutron star interiors. Easson, I. Abstract The paper examines the hypothesis that the plasma of charged particles in the fluid core corotates with the solid crust as a result of the large interior magnetic field over very long time scales comparable to the apparent age of pulsars. In order to enforce approximate corotation of the interior plasma in a neutron star with the crust, the magnetic field in the fluid interior must be stronger than a minimum value governed by the rotation period and its first and second derivatives. If the field is below the minimum required value, viscocity enforces approximate corotation through the formation of an Ekman layer and pumping into and out of it. The shear of the plasma velocity is sufficient to magnify any magnetic field in a small fraction of the apparent pulsar age, so all known pulsars should have interior magnetic fields at least as large as the minimum calculated here. Finally, the effective moment of inertia of the plasma in the fluid core is shown to depend on the structure of the field there, contrary to previous assumptions. Publication: The Astrophysical Journal Pub Date: October 1979 DOI: 10.1086/157432 Bibcode: 1979ApJ...233..711E Keywords: Astrophysics; Magnetohydrodynamics; Neutron Stars; Pulsars; Stellar Interiors; Boundary Layer Transition; Long Term Effects; Periodic Variations; Stellar Magnetic Fields; Stress Tensors; Astrophysics; Magnetic Fields:Stellar Interiors; Neutron Stars:Plasma; Pulsars:Pulse Structure full text sources ADS |