UNIVERSALITY IN OSCILLATION MODES OF SUPERFLUID NEUTRON STARS?
Publication in refereed journal


Times Cited
Web of Science3WOS source URL (as at 25/09/2020) Click here for the latest count
Altmetrics Information
.

Other information
AbstractIt has been well established that the f-mode of relativistic ordinary fluid neutron stars displays a universal scaling behavior. Here, we study whether the "ordinary" f(o)- and "superfluid" f(s)-modes of superfluid neutron stars also show similar universal behavior. We first consider a simple case where the neutron superfluid and normal fluid are decoupled, and with each fluid modeled by a polytropic equation of state. We find that the f(o)-mode obeys the same scaling laws as established for the f-mode of ordinary fluid stars. However, the oscillation frequency of the f(s)-mode obeys a different scaling law, which can be derived analytically from a homogenous two-fluid stellar model in Newtonian gravity. Next the coupling effect between the two fluids is studied via a parameterized model of entrainment. We find that the coupling in general breaks the universal behavior seen in the case of decoupled fluids. Based on a relativistic variational principle, an approximated expression is derived for the first-order shift of the f(s)-mode squared frequency due to the entrainment.
All Author(s) ListWong KS, Lin LM, Leung PT
Journal nameAstrophysical Journal
Year2009
Month7
Day10
Volume Number699
Issue Number2
PublisherAmerican Astronomical Society
Pages1809 - 1821
ISSN0004-637X
eISSN1538-4357
LanguagesEnglish-United Kingdom
Keywordsdense matter; equation of state; gravitational waves; stars: neutron; stars: oscillations
Web of Science Subject CategoriesAstronomy & Astrophysics; ASTRONOMY & ASTROPHYSICS

Last updated on 2020-26-09 at 01:20