General relativistic hydrodynamics with viscosity: contraction, catastrophic collapse, and disk formation in hypermassive neutron stars

Details General relativistic hydrodynamics with viscosity: contraction, catastrophic collapse, and disk formation in hypermassive neutron stars General relativistic hydrodynamics with viscosity: contraction, catastrophic collapse, and disk formation in hypermassive neutron stars

2004-02-20

arxiv.org/abs/astro-ph/0402502v1

Phys.Rev. D69 (2004) 104030

Astronomy and Astrophysics

Astrophysics

27 pages, 21 figures, accepted for publication in Phys. Rev. D

Scientific paper

10.1103/PhysRevD.69.104030

Viscosity and magnetic fields drive differentially rotating stars toward uniform rotation, which has important consequences in many astrophysical contexts. For example, merging binary neutron stars can form a "hypermassive" remnant, i.e. a differentially rotating star with a mass greater than the maximum allowed by uniform rotation. The removal of the centrifugal support provided by differential rotation can lead to delayed collapse of the remnant to a black hole, accompanied by a burst of gravitational radiation. Both magnetic fields and viscosity alter the structure of differentially rotating stars on secular timescales, making numerical tracking of the evolution difficult. Here, we present the first simulations of rapidly rotating stars with shear viscosity in full general relativity. We self-consistently include viscosity in our relativistic hydrodynamic code to solve the relativistic Navier-Stokes equations both in axisymmetry and in full 3+1 dimensions. In axisymmetry, we follow secular evolution with high resolution over dozens of rotation periods (thousands of M). We find that viscosity operating in a hypermassive star generically leads to the formation of a compact, uniformly rotating core surrounded by a low-density disk. These uniformly rotating cores are often, but not always, unstable to gravitational collapse. In the unstable cases, we follow the collapse and determine the mass and the spin of the final black hole and ambient disk. In all cases studied, the rest mass of the resulting disk is found to be 10-20% of the original star, whether surrounding a uniformly rotating core or a rotating black hole. This study foreshadows more detailed, future simulations of secular processes, including magnetic effects, in relativistic stars.

Affiliated with

Also associated with

No associations

Rating

General relativistic hydrodynamics with viscosity: contraction, catastrophic collapse, and disk formation in hypermassive neutron stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with General relativistic hydrodynamics with viscosity: contraction, catastrophic collapse, and disk formation in hypermassive neutron stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and General relativistic hydrodynamics with viscosity: contraction, catastrophic collapse, and disk formation in hypermassive neutron stars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-221310