Quaking neutron star deriving radiative power of oscillating magneto-dipole emission from energy of Alfv\'en seismic vibrations

TL;DR

This paper explores how magnetic field decay in quaking neutron stars leads to energy conversion from seismic vibrations into magneto-dipole radiation, causing the star's vibration period to lengthen, with implications for understanding magnetar emissions.

Contribution

It demonstrates the mechanism of magnetic-field-decay-induced energy conversion from Alfvén vibrations to magneto-dipole radiation in neutron stars.

Findings

Magnetic field decay causes lengthening of vibration periods.

Energy from seismic vibrations is converted into electromagnetic radiation.

The model explains observed magnetar emission behaviors.

Abstract

It is shown that depletion of the magnetic field pressure in a quaking neutron star undergoing Lorentz-force-driven torsional seismic vibrations about axis of its dipole magnetic moment is accompanied by the loss of vibration energy of the star that causes its vibration period to lengthen at a rate proportional to the rate of magnetic field decay. Highlighted is the magnetic-field-decay induced conversion of the energy of differentially rotational Alfv\'en vibrations into the energy of oscillating magneto-dipole radiation. A set of representative examples of magnetic field decay illustrating the vibration energy powered emission with elongating periods produced by quaking neutron star are considered and discussed in the context of theory of magnetars.