04/30/02
Gondek-Rosinska Dorota LUTH, Observatoire de Paris
5 Pl Jules Janseen SF2A-
92 195 Meudon, France
Presentation 1 : Oral
Viscosity driven bar mode instability in rapidly rotating neutron stars and strange stars
Gondek-Rosinska Dorota, Gourgoulhon Eric
The laser interferometric gravitational wave detectors should be fully operationally soon. Triaxial instabilities of rotating neutron stars can play an important role as an emission mechanism of gravitational waves in the frequency range of forthcoming LIGO/VIRGO interferometric detectors. We study the secular triaxial instability of rigidly rotating neutron stars and strange stars in general relativity. At the Newtonian limit, this corresponds to the bifurcation point between the Maclaurin spheroid and the Jacobi ellipsoids. We find that stabilizating effect of relativity in the case of homogeneous fluid bodies is much weaker than showed by Shapiro \& Zane (1998) post-Newtonian calculations. In the case of strange stars we find that the bar mode instability is possible for a broad ranges of gravitational masses and rotational frequencies.