The University of Southampton
University of Southampton Institutional Repository

Axial quasi-normal modes of neutron stars: accounting for the superfluid in the crust

Axial quasi-normal modes of neutron stars: accounting for the superfluid in the crust
Axial quasi-normal modes of neutron stars: accounting for the superfluid in the crust
We present the results of the first study of global oscillations of relativistic stars with both elastic crusts and interpenetrating superfluid components. For simplicity, we focus on the axial quasi-normal modes. Our results demonstrate that the torsional crust modes are essentially unaffected by the coupling to the gravitational field. This is as expected since these oscillations are known to be weak gravitational-wave sources. In contrast, the presence of a loosely coupled superfluid neutron component in the crust can have a significant effect on the oscillation spectrum. We show that the entrainment between the superfluid and the crust nuclei is a key parameter in the problem. Our analysis highlights the need for a more detailed understanding of the coupled crust-superfluid at the microphysical level. Our numerical results have, even though we have not considered magnetized stars, some relevance for efforts to carry out seismology based on quasi-periodic oscillations observed in the tails of magnetar flares. In particular, we argue that the sensitive dependence on the entrainment may have to be accounted for in attempts to match theoretical models to observational data.
0264-9381
155016
Samuelsson, Lars
ce25b720-ee5b-4b1a-af84-c38a41399a62
Andersson, Nils
2dd6d1ee-cefd-478a-b1ac-e6feedafe304
Samuelsson, Lars
ce25b720-ee5b-4b1a-af84-c38a41399a62
Andersson, Nils
2dd6d1ee-cefd-478a-b1ac-e6feedafe304

Samuelsson, Lars and Andersson, Nils (2009) Axial quasi-normal modes of neutron stars: accounting for the superfluid in the crust. Classical and Quantum Gravity, 26 (15), 155016. (doi:10.1088/0264-9381/26/15/155016).

Record type: Article

Abstract

We present the results of the first study of global oscillations of relativistic stars with both elastic crusts and interpenetrating superfluid components. For simplicity, we focus on the axial quasi-normal modes. Our results demonstrate that the torsional crust modes are essentially unaffected by the coupling to the gravitational field. This is as expected since these oscillations are known to be weak gravitational-wave sources. In contrast, the presence of a loosely coupled superfluid neutron component in the crust can have a significant effect on the oscillation spectrum. We show that the entrainment between the superfluid and the crust nuclei is a key parameter in the problem. Our analysis highlights the need for a more detailed understanding of the coupled crust-superfluid at the microphysical level. Our numerical results have, even though we have not considered magnetized stars, some relevance for efforts to carry out seismology based on quasi-periodic oscillations observed in the tails of magnetar flares. In particular, we argue that the sensitive dependence on the entrainment may have to be accounted for in attempts to match theoretical models to observational data.

This record has no associated files available for download.

More information

Published date: 2009
Organisations: Applied Mathematics

Identifiers

Local EPrints ID: 151305
URI: http://eprints.soton.ac.uk/id/eprint/151305
ISSN: 0264-9381
PURE UUID: 088c649f-d642-4194-a8d1-9d99c0cc92f0
ORCID for Nils Andersson: ORCID iD orcid.org/0000-0001-8550-3843

Catalogue record

Date deposited: 10 May 2010 10:42
Last modified: 08 Jan 2022 02:48

Export record

Altmetrics

Contributors

Author: Lars Samuelsson
Author: Nils Andersson ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×