2010/07/31 by Francois Foucart, François Foucart, Matthew Duez +3
Physics and Astronomy · #Accretion (finance) #Astrophysical Phenomena and Observations #Astrophysics #Black hole (networking) #Gamma-ray bursts and supernovae #General relativity #Neutron star #Physics #Pulsars and Gravitational Waves Research #Spin (aerodynamics) #Spin-flip #astro-ph.HE #gr-qc
paper · pdf · doi:10.1103/physrevd.83.024005
published as Phys.Rev.D83:024005,2011 · 15 pages, 13 figures
arxiv created 2011/01/06 · openalex publication_date 2011/01/06 · arxiv updated 2011/02/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The spin of black holes in black hole-neutron star binaries can have a strong influence on the merger dynamics and the post-merger state; a wide variety of spin magnitudes and orientations are expected to occur in nature. In this paper, we report the first simulations in full general relativity of black hole-neutron star mergers with misaligned black hole spin. We vary the spin magnitude from aBH/MBH=0 to aBH/MBH=0.9 for aligned cases, and we vary the misalignment angle from 0 to 80\ifmmode^∘\else\textdegree\fi for aBH/MBH=0.5. We restrict our study to 3\ensuremath\mathbin:1 mass-ratio systems and use a simple \ensuremathΓ-law equation of state. We find that the misalignment angle has a strong effect on the mass of the post-merger accretion disk, but only for angles greater than \ensuremath≈40\ifmmode^∘\else\textdegree\fi. Although the disk mass varies significantly with spin magnitude and misalignment angle, we find that all disks have very similar lifetimes \ensuremath≈100 ms. Their thermal and rotational profiles are also very similar. For a misaligned merger, the disk is tilted with respect to the final black hole's spin axis. This will cause the disk to precess, but on a time scale longer than the accretion time. In all cases, we find promising setups for gamma-ray burst production: the disks are hot, thick, and hyperaccreting, and a baryon-clear region exists above the black hole.