Instabilities in rotating relativistic stars driven by viscosity

Motoyuki Saijo, Eric Gourgoulhon

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We investigate the instability driven by viscosity in rotating relativistic stars by means of an iterative approach. We focus on polytropic rotating equilibrium stars and impose an m=2 perturbation in the lapse. We vary both the stiffness of the equation of state and the compactness of the star to study these factors on the critical value T/W for the instability. For a rigidly rotating star, the criterion T/W, where T is the rotational kinetic energy and W the gravitational binding energy, mainly depends on the compactness of the star and takes values around 0.13-0.16, which slightly differ from that of Newtonian incompressible stars (∼0.14). For differentially rotating stars, the critical value of T/W is found to span the range 0.17-0.25. The value is significantly larger than in the rigidly rotating case with the same compactness of the star. Finally we discuss the possibility of detecting gravitational waves from viscosity-driven instabilities using ground-based interferometers.

Original languageEnglish
Pages (from-to)481-485
Number of pages5
JournalAstrophysics and Space Science
Volume308
Issue number1-4
DOIs
Publication statusPublished - 2007 Apr
Externally publishedYes

Fingerprint

viscosity
stars
void ratio
interferometer
equation of state
kinetic energy
stiffness
perturbation
gravitational binding energy
energy
gravitational waves
equations of state
interferometers

Keywords

  • Gravitational waves
  • Instabilities
  • Relativity
  • Stars: rotation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Instabilities in rotating relativistic stars driven by viscosity. / Saijo, Motoyuki; Gourgoulhon, Eric.

In: Astrophysics and Space Science, Vol. 308, No. 1-4, 04.2007, p. 481-485.

Research output: Contribution to journalArticle

Saijo, Motoyuki ; Gourgoulhon, Eric. / Instabilities in rotating relativistic stars driven by viscosity. In: Astrophysics and Space Science. 2007 ; Vol. 308, No. 1-4. pp. 481-485.
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