Gravitational radiation from rotational instabilites in compact stellar cores with stiff equations of state
Abstract
We carry out 3D numerical simulations of the dynamical instability in rapidly rotating stars initially modeled as polytropes with n=1.5,1.0, and 0.5. The calculations are done with a SPH code using Newtonian gravity, and the gravitational radiation is calculated in the quadrupole limit. All models develop the global m=2 bar mode, with mass and angular momentum being shed from the ends of the bar in two trailing spiral arms. The models then undergo successive episodes of core recontraction and spiral arm ejection, with the number of these episodes increasing as n decreases: this results in longer-lived gravitational wave signals for stiffer models. This instability may operate in a stellar core that has expended its nuclear fuel and is prevented from further collapse due to centrifugal forces. The actual values of the gravitational radiation amplitudes and frequencies depend sensitively on the radius of the star Req at which the instability develops.
- Publication:
-
Physical Review D
- Pub Date:
- December 1996
- DOI:
- 10.1103/PhysRevD.54.7278
- arXiv:
- arXiv:gr-qc/9611033
- Bibcode:
- 1996PhRvD..54.7278H
- Keywords:
-
- 04.30.Db;
- 04.80.Nn;
- 95.55.Ym;
- 97.60.-s;
- Wave generation and sources;
- Gravitational wave detectors and experiments;
- Gravitational radiation detectors;
- mass spectrometers;
- and other instrumentation and techniques;
- Late stages of stellar evolution;
- General Relativity and Quantum Cosmology;
- Astrophysics
- E-Print:
- 39 pages, uses Latex 2.09. To be published in the Dec. 15, 1996 issue of Physical Review D. 21 figures (bitmapped). Originals available in compressed Postscript format at ftp://zonker.drexel.edu/papers/bars/