Critical phenomena in neutron stars: II. Head-on collisions
Abstract
We consider the head-on collision of equal-mass neutron stars boosted towards each other and we study the behaviour of such systems near the threshold of black-hole formation. In particular, we confirm the previous findings by Jin K J et al (2007 Phys. Rev. Lett 98 131101) that a type I critical phenomenon can be observed by fine-tuning the initial mass of the two neutron stars. At the same time, we argue against the interpretation that the critical solution is not a perturbed spherical star and show instead that the metastable star corresponds to a (perturbed) equilibrium solution on the unstable branch of the equilibrium configurations. As a result, the head-on collision of two neutron stars near the critical threshold can be seen as a transition in the space of configurations from an initial stable solution over to a critical metastable one which can either migrate to a stable solution or collapse to a black hole. The critical exponent for this process shows a fine structure which was already observed in the case of the critical collapse of scalar fields but never before for perfect fluids.
- Publication:
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Classical and Quantum Gravity
- Pub Date:
- December 2010
- DOI:
- 10.1088/0264-9381/27/23/235016
- arXiv:
- arXiv:1007.2797
- Bibcode:
- 2010CQGra..27w5016K
- Keywords:
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- General Relativity and Quantum Cosmology;
- Mathematical Physics
- E-Print:
- 15 pages, 19 figures