S E M I N A R IDepartament d'Astronomia i Astrofísica
Universitat de València
Numerical Study of Nonlinear R-modes in Neutron Stars
LUTH, Meudon, France
Seminari del departament d'Astronomia i Astrofísica
Dijous 18 novembre 2004
R-modes of rotating neutron stars are unstable growing modes driven by the back reaction of the gravitational radiation the modes themselves emit. The discovery of the r-mode instability has attracted much attention due to its possible implication on the spin rates of neutron stars, and the possibility of being a promising source of gravitational waves detectable by advanced gravitational wave detectors. However, whether this instability is astrophysically relevant or not depends critically on how large the r-mode amplitude can grow up to. In this talk, we will present our fully nonlinear neutron star simulation and show that a large amplitude r-mode will couple nonlinearly to other fluid modes in a way that leads to a catastrophic decay of the r-mode. We identify the mode-coupling mechanism responsible for this decay. The limit this mechanism imposes on the r-mode amplitude is studied.