Freely precessing neutron stars: model and observations
Freely precessing neutron stars: model and observations
We present a model of a freely precessing neutron star, which is then compared against pulsar observations. The aim is to draw conclusions regarding the structure of the star, and to test theoretical ideas of crust–core coupling and superfluidity. We argue that, on theoretical grounds, it is likely that the core neutron superfluid does not participate in the free precession of the crust. We apply our model to the handful of proposed observations of free precession that have appeared in the literature. Assuming crust-only precession, we find that all but one of the observations are consistent with there being no pinned crustal superfluid at all; the maximum amount of pinned superfluid consistent with the observations is about 10-10 of the total stellar moment of inertia. However, the observations do not rule out the possibility that the crust and neutron superfluid core precess as a single unit. In this case the maximum amount of pinned superfluid consistent with the observations is about 10-8 of the total stellar moment of inertia. Both of these values are many orders of magnitude less than the 10-2 value predicted by many theories of pulsar glitches. We conclude that superfluid pinning, at least as it affects free precession, needs to be reconsidered.
811-824
Jones, D.I.
b8f3e32c-d537-445a-a1e4-7436f472e160
Andersson, N.A.
2dd6d1ee-cefd-478a-b1ac-e6feedafe304
July 2001
Jones, D.I.
b8f3e32c-d537-445a-a1e4-7436f472e160
Andersson, N.A.
2dd6d1ee-cefd-478a-b1ac-e6feedafe304
Jones, D.I. and Andersson, N.A.
(2001)
Freely precessing neutron stars: model and observations.
Monthly Notices of the Royal Astronomical Society, 324 (4), .
(doi:10.1046/j.1365-8711.2001.04251.x).
Abstract
We present a model of a freely precessing neutron star, which is then compared against pulsar observations. The aim is to draw conclusions regarding the structure of the star, and to test theoretical ideas of crust–core coupling and superfluidity. We argue that, on theoretical grounds, it is likely that the core neutron superfluid does not participate in the free precession of the crust. We apply our model to the handful of proposed observations of free precession that have appeared in the literature. Assuming crust-only precession, we find that all but one of the observations are consistent with there being no pinned crustal superfluid at all; the maximum amount of pinned superfluid consistent with the observations is about 10-10 of the total stellar moment of inertia. However, the observations do not rule out the possibility that the crust and neutron superfluid core precess as a single unit. In this case the maximum amount of pinned superfluid consistent with the observations is about 10-8 of the total stellar moment of inertia. Both of these values are many orders of magnitude less than the 10-2 value predicted by many theories of pulsar glitches. We conclude that superfluid pinning, at least as it affects free precession, needs to be reconsidered.
This record has no associated files available for download.
More information
Published date: July 2001
Identifiers
Local EPrints ID: 29440
URI: http://eprints.soton.ac.uk/id/eprint/29440
ISSN: 1365-2966
PURE UUID: 272f620d-2ca4-467b-9393-f84943839bd7
Catalogue record
Date deposited: 12 May 2006
Last modified: 16 Mar 2024 03:06
Export record
Altmetrics
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
