Relativistic simulations of the phase-transition-induced collapse of neutron stars |
| |
| Authors: | Ernazar B Abdikamalov Harald Dimmelmeier Luciano Rezzolla John C Miller |
| |
| Institution: | International School of Advanced Studies (SISSA) and INFN, Via Beirut 2–4, I-34014 Trieste, Italy;Institute of Nuclear Physics, Uzbekistan Academy of Sciences, Ulughbek, Uzbekistan;Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece;Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Strasse 1, D-85741 Garching, Germany;Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, D-14476 Golm, Germany;Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA;INFN, Department of Physics, University of Trieste, Trieste, Italy;Department of Physics (Astrophysics), University of Oxford, Keble Road, Oxford OX1 3RH |
| |
| Abstract: | An increase in the central density of a neutron star may trigger a phase transition from hadronic matter to deconfined quark matter in the core, causing it to collapse to a more compact hybrid star configuration. We present a study of this, building on previous work by Lin et al.. We follow them in considering a supersonic phase transition and using a simplified equation of state, but our calculations are general relativistic (using 2D simulations in the conformally flat approximation) as compared with their 3D Newtonian treatment. We also improved the treatment of the initial phase transformation, avoiding the introduction of artificial convection. As before, we find that the emitted gravitational wave spectrum is dominated by the fundamental quasi-radial and quadrupolar pulsation modes but the strain amplitudes are much smaller than suggested previously, which is disappointing for the detection prospects. However, we see significantly smaller damping and observe a non-linear mode resonance which substantially enhances the emission in some cases. We explain the damping mechanisms operating, giving a different view from the previous work. Finally, we discuss the detectability of the gravitational waves, showing that the signal-to-noise ratio for current or second generation interferometers could be high enough to detect such events in our Galaxy, although third generation detectors would be needed to observe them out to the Virgo cluster, which would be necessary for having a reasonable event rate. |
| |
| Keywords: | hydrodynamics relativity methods: numerical stars: neutron stars: oscillations stars: rotation |
|
|
