Open AccessDynamical instability of differentially rotating stars
Author(s) -
Shibata Masaru,
Karino Shigeyuki,
Eriguchi Yoshiharu
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05724.x
Subject(s) - physics , polytropic process , polytrope , stars , gravitational wave , instability , classical mechanics , astrophysics , adiabatic process , radius , gravitational energy , differential rotation , perturbation (astronomy) , amplitude , quadrupole , kinetic energy , mechanics , astronomy , quantum mechanics , computer security , computer science
We study the dynamical instability against bar‐mode deformation of differentially rotating stars. We performed numerical simulation and linear perturbation analysis adopting polytropic equations of state with the polytropic index n = 1 . It is found that rotating stars of a high degree of differential rotation are dynamically unstable even for the ratio of the kinetic energy to the gravitational potential energy of O (0.01). Gravitational waves from the final non‐axisymmetric quasi‐stationary states are calculated in the quadrupole formula. For rotating stars of mass 1.4 M ⊙ and radius several 10 km, gravitational waves have frequency several 100 Hz and effective amplitude ∼5 × 10 −22 at a distance of ∼100 Mpc.