On the free-precession candidate PSR B1828-11: Evidence for increasing deformation

Download statistics - Document (COUNTER):

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

Repository version

To cite the version in the repository, please use this identifier: https://doi.org/10.15488/5193

Selected time period:


Sum total of downloads: 66

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.
License of this version: CC BY 4.0 Unported
Document Type: Article
Publishing status: publishedVersion
Issue Date: 2017
Appears in Collections:Fakultät für Mathematik und Physik

distribution of downloads over the selected time period:

downloads by country:

pos. country downloads
total perc.
1 image of flag of Germany Germany 26 39.39%
2 image of flag of United States United States 22 33.33%
3 image of flag of China China 6 9.09%
4 image of flag of Vietnam Vietnam 2 3.03%
5 image of flag of Ukraine Ukraine 2 3.03%
6 image of flag of Russian Federation Russian Federation 2 3.03%
7 image of flag of Norway Norway 2 3.03%
8 image of flag of Taiwan Taiwan 1 1.52%
9 image of flag of Netherlands Netherlands 1 1.52%
10 image of flag of Belgium Belgium 1 1.52%
    other countries 1 1.52%

Further download figures and rankings:


Zur Erhebung der Downloadstatistiken kommen entsprechend dem „COUNTER Code of Practice for e-Resources“ international anerkannte Regeln und Normen zur Anwendung. COUNTER ist eine internationale Non-Profit-Organisation, in der Bibliotheksverbände, Datenbankanbieter und Verlage gemeinsam an Standards zur Erhebung, Speicherung und Verarbeitung von Nutzungsdaten elektronischer Ressourcen arbeiten, welche so Objektivität und Vergleichbarkeit gewährleisten sollen. Es werden hierbei ausschließlich Zugriffe auf die entsprechenden Volltexte ausgewertet, keine Aufrufe der Website an sich.

Search the repository