dc.identifier.uri |
http://dx.doi.org/10.15488/5193 |
|
dc.identifier.uri |
https://www.repo.uni-hannover.de/handle/123456789/5240 |
|
dc.contributor.author |
Ashton, G.
|
|
dc.contributor.author |
Jones, D.I.
|
|
dc.contributor.author |
Prix, Reinhard
|
|
dc.date.accessioned |
2019-08-15T11:13:37Z |
|
dc.date.available |
2019-08-15T11:13:37Z |
|
dc.date.issued |
2017 |
|
dc.identifier.citation |
Ashton, G.; Jones, D.I.; Prix, R.: On the free-precession candidate PSR B1828-11: Evidence for increasing deformation. In: Monthly Notices of the Royal Astronomical Society 465 (2017), Nr. 3, S. 164-178. DOI: https://doi.org/10.1093/mnras/stx060 |
|
dc.description.abstract |
We observe that the periodic variations in spin-down rate and beam-width of the radio pulsar PSR B1828-11 are getting faster. In the context of a free precession model, this corresponds to a decrease in the precession period $P_{\mathrm{fp}}$. We investigate how a precession model can account for such a decrease in $P_{\mathrm{fp}}$, in terms of an increase over time in the absolute biaxial deformation ($|\epsilon_{\mathrm{p}}|{\sim}10^{-8}$) of this pulsar. We perform a Bayesian model comparison against the 'base' precession model (with constant $\epsilon_{\mathrm{p}}$) developed in Ashton et al (2016), and we obtain decisive odds in favour of a time-varying deformation. We study two types of time-variation: (i) a linear drift with a posterior estimate of $\dot{\epsilon}_{\mathrm{p}}{\sim}10^{-18}\,\mathrm{s}^{-1}$ and odds of $10^{75}$ compared to the base-model, and (ii) $N$ discrete positive jumps in $\epsilon_{\mathrm{p}}$ with very similar odds to the linear $\epsilon_{\mathrm{p}}$-drift model. The physical mechanism explaining this behaviour is unclear, but the observation could provide a crucial probe of the interior physics of neutron stars. We also place an upper bound on the rate at which the precessional motion is damped, and translate this into a bound on a dissipative mutual friction-type coupling between the star's crust and core. |
eng |
dc.language.iso |
eng |
|
dc.publisher |
Oxford : Oxford University Press (OUP) |
|
dc.relation.ispartofseries |
Monthly Notices of the Royal Astronomical Society 465 (2017), Nr. 3 |
|
dc.rights |
CC BY 4.0 Unported |
|
dc.rights.uri |
https://creativecommons.org/licenses/by/4.0/ |
|
dc.subject |
Pulsar |
eng |
dc.subject |
Physics |
eng |
dc.subject |
Periodic graph (geometry) |
eng |
dc.subject |
Neutron star |
eng |
dc.subject |
Astrophysics |
eng |
dc.subject |
Deformation (mechanics) |
eng |
dc.subject |
Upper and lower bounds |
eng |
dc.subject |
Precession |
eng |
dc.subject.ddc |
520 | Astronomie, Kartographie
|
ger |
dc.title |
On the free-precession candidate PSR B1828-11: Evidence for increasing deformation |
|
dc.type |
Article |
|
dc.type |
Text |
|
dc.relation.issn |
0035-8711 |
|
dc.relation.doi |
https://doi.org/10.1093/mnras/stx060 |
|
dc.bibliographicCitation.issue |
3 |
|
dc.bibliographicCitation.volume |
465 |
|
dc.bibliographicCitation.firstPage |
164 |
|
dc.bibliographicCitation.lastPage |
178 |
|
dc.description.version |
publishedVersion |
|
tib.accessRights |
frei zug�nglich |
|