A Bar-Unstable Hypermassive Neutron Star (Spiral Arms):
T/W ~ 0.26


The green line represents the division between stable (white) and bar-unstable (black) hypermassive neutron stars. The division is at T/W ~ 0.24-0.25. Below we evolve a configuration with T/W ~ 0.26, in the unstable region. The yellow arrow indicates the specific model we are examining.

Scene 1: Initial Conditions of Bar-Unstable Star

Scene 2: Evolution of Bar-Unstable Star

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This animation shows the evolution of the outer surface of the neutron star. It loses stability and axisymmetry, forming spiral-arm-like structures.

Scene 3: Density profile of Bar-Unstable Star

indicates the central density, while indicates the maximum density.

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After time advances the star exhibits instability, forming spiral-arm-like structures.

Scene 4: Generation of Gravitational Radiation

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This animation shows the time evolution of a two-dimensional color representation of the gravitational wave amplitudes in a plane containing the rotation axis. At large distances, the waves assume a quadrupole-like angular dependence.

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In this animation we watch the evolution of the gravitational waveform measure by the height above a plane containing the rotation axis.

last updated 5 Nov 14 aakhan3