6533b829fe1ef96bd128aeb3
RESEARCH PRODUCT
On the black hole from merging binary neutron stars: how fast can it spin?
Filippo GaleazziWolfgang KastaunJosé A. FontDaniela AlicLuciano Rezzollasubject
PhysicsNuclear and High Energy PhysicsAngular momentumAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesGeneral Relativity and Quantum Cosmology (gr-qc)General Relativity and Quantum CosmologyBlack holeGeneral Relativity and Quantum CosmologyRotating black holeBinary black holeTotal angular momentum quantum numberQuantum mechanicsExtremal black holeStellar black holeSpin-flipdescription
The merger of two neutron stars will in general lead to the formation of a torus surrounding a black hole whose rotational energy can be tapped to potentially power a short gamma-ray burst. We have studied the merger of equal-mass binaries with spins aligned with the orbital angular momentum to determine the maximum spin the black hole can reach. Our initial data consists of irrotational binaries to which we add various amounts of rotation to increase the total angular momentum. Although the initial data violates the constraint equations, the use of the constraint-damping CCZ4 formulation yields evolutions with violations smaller than those with irrotational initial data and standard formulations. Interestingly, we find that a limit of $J/M^2 \simeq 0.89$ exists for the dimensionless spin and that any additional angular momentum given to the binary ends up in the torus rather than in the black hole, thus providing another nontrivial example supporting the cosmic censorship hypothesis.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-01-30 |