Rapid Spin Deceleration of Magnetized Proto-Neutron Stars via Asymmetric Neutrino Emission

TL;DR

This paper demonstrates that asymmetric neutrino absorption in toroidal magnetic fields can cause rapid spin deceleration of proto-neutron stars, potentially explaining the observed rapid deceleration of magnetars.

Contribution

It introduces the first calculation of neutron star spin deceleration due to asymmetric neutrino absorption in toroidal magnetic fields using relativistic mean field theory.

Findings

Deceleration can be significantly larger than magnetic dipole braking.

Toroidal magnetic fields play a crucial role in spin deceleration.

Potential explanation for rapid past deceleration of magnetars.

Abstract

We calculate the spin deceleration of proto-neutron stars by asymmetric neutrino absorption in the context of a fully relativistic mean field theory. We calculate for the first time the spin deceleration of neutron stars due to asymmetric neutrino absorption in a toroidal magnetic field configurations. We find a surprising effect that the deceleration can much larger for asymmetric neutrino absorption in a toroidal magnetic field than the usually presumed braking due to magnetic dipole radiation. This may explain the observation that magnetars appear to have had a more rapid deceleration in the past.