Gravitational radiation from nonaxisymmetric spherical Couette flow in a neutron star

Abstract

The gravitational-wave signal generated by global, nonaxisymmetric shear flows in a neutron star is calculated numerically by integrating the incompressible Navier-Stokes equation in a spherical, differentially rotating shell. At Reynolds numbers Re 3#103 the laminar Stokes flow is unstable, and helical, oscillating Taylor-Görtler vortices develop. The gravitational-wave strain generated by the resulting kinetic energy fluctuations is computed in both plus and cross polarizations as a function of time. It is found that the signal-to-noise ratio for a coherent, 108 s integration with LIGO II scales as 6.5[Q*/(104 rad s1)]7/2 for a star at 1 kpc with angular velocity Q*. This should be regarde..