2001/10/31 by Lee Lindblom, B. J. Owen, Benjamin J. Owen · 3 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #High-pressure geophysics and materials #Pulsars and Gravitational Waves Research #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.65.063006
published as Phys.Rev. D65 (2002) 063006 · final PRD version, minor typos etc corrected
arxiv created 2002/01/23 · openalex publication_date 2002/03/04 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Neutron stars are expected to contain a significant number of hyperons in addition to protons and neutrons in the highest density portions of their cores. Following the work of Jones, we calculate the coefficient of bulk viscosity due to nonleptonic weak interactions involving hyperons in neutron-star cores, including new relativistic and superfluid effects. We evaluate the influence of this new bulk viscosity on the gravitational radiation driven instability in the r-modes. We find that the instability is completely suppressed in stars with cores cooler than a few times 109 K, but that stars rotating more rapidly than 10--30% of maximum are unstable for temperatures around 1010 K. Since neutron-star cores are expected to cool to a few times 109 K within seconds (much shorter than the r-mode instability growth time) due to direct Urca processes, we conclude that the gravitational radiation instability will be suppressed in young neutron stars before it can significantly change the angular momentum of the star.