QHD description of the instability in strongly magnetized neutron stars

Abstract

We study the quantum hadrodynamic (QHD) equation of state for neutron stars (with and without including hyperons) in the presence of strong magnetic fields. The calculated adiabatic index for magnetized neutron stars based on the QHD model exhibit rapid changes with density. This may provide some insight into the mechanism of star-quakes and flares in magnetars. We also investigate the strong magnetic field effects on the moments of inertia of neutron stars. The change of the moments of inertia associated with emitted magnetic flares is shown to match well with observed glitches in some magnetars. In our QHD model, the deduced masses and radii of neutron stars without hyperons are consistent with recent observations of high mass neutron stars, while those with hyperons turn out to be less than the recent high mass neutron star.