Speaker
Description
With the onset of the era of gravitational-wave astronomy, the search for continuous gravitational
waves, which remain undetected to date, has intensified in more ways than one. Rapidly rotating
neutron stars with non-axisymmetrical deformations of their crusts are the main targets for CGW
searches. The extent of this quadrupolar deformation (commonly referred to as mountains of the
neutron star) is measured by the maximum ellipticity that can be sustained by the crust of a neutron
star and it places an upper limit on the CGW amplitudes emitted by such systems. In this paper,
following the example set by [1] and [2], we calculate the maximum ellipticity of a neutron star crust
generated by the Lorentz force exerted on it by the star’s internal magnetic fields. We focus on
three different scenarios for different configurations of the star’s magnetic fields to calculate the size
of the neutron star mountain formed using the scheme devised by [1]. We show that the fiducial
ellipticity of the star is enhanced in the presence of strong magnetic fields and it is further enhanced
when components of the magnetic field are trapped in the crust. This promising result allows us
to estimate the increased size of the neutron star mountains which will be vital when the imminent
first detection of continuous gravitational waves happens.
References
[1] F. Gittins, N. Andersson, and D. I. Jones. “Modelling neutron star mountains”. In: 500.4 (Jan.
2021), pp. 5570–5582. doi: 10.1093/mnras/staa3635. arXiv: 2009.12794 [astro-ph.HE].
[2] J A Morales and C J Horowitz. “Neutron star crust can support a large ellipticity”. In: Monthly
Notices of the Royal Astronomical Society 517.4 (Oct. 2022), pp. 5610–5616. doi: 10.1093/
mnras/stac3058. url: https://doi.org/10.1093%5C%2Fmnras%5C%2Fstac3058.
