2007/05/13 by G. M. Manca, L. Baiotti, Luca Baiotti +3 · 3 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Gamma-ray bursts and supernovae #Pulsars and Gravitational Waves Research #astro-ph #gr-qc
paper · pdf · doi:10.1088/0264-9381/24/12/s12
published as Class.Quant.Grav.24:S171-S186,2007 · To appear on CQG, NFNR special issue. 16 pages, 5 color figures, movies from http://www.fis.unipr.it/numrel/BarMode/ResearchBarMode.html
arxiv created 2007/05/13 · openalex publication_date 2007/05/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present new results on dynamical instabilities in rapidly rotating relativistic stars. In particular, using numerical simulations in full general relativity, we analyse the effects that the stellar compactness has on the threshold for the onset of the dynamical bar-mode instability, as well as on the appearance of other dynamical instabilities. By using an extrapolation technique developed and tested in our previous study (Baiotti L et al 2007 Phys. Rev. D 75 044023), we explicitly determine the threshold for a wide range of compactnesses using four sequences of models of constant baryonic mass comprising a total of 59 stellar models. Our calculation of the threshold is in good agreement with the Newtonian prediction and improves the previous post-Newtonian estimates. In addition, we find that for stars with sufficiently large mass and compactness, the m = 3 deformation is the fastest growing one. For all of the models considered, the non-axisymmetric instability is suppressed on a dynamical timescale with an m = 1 deformation dominating the final stages of the instability. These results, together with those presented in Baiotti L et al (2007 Phys. Rev. D 75 044023), suggest that an m = 1 deformation represents a general and late-time feature of non-axisymmetric dynamical instabilities both in full general relativity and in Newtonian gravity.