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arXiv · 1310.8290

Gravitational wave signatures in black-hole-forming core collapse

Pablo Cerdá-Durán·Nicolas DeBrye·Miguel A Aloy·José A Font·Martin Obergaulinger
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Abstract

We present numerical simulations in general relativity of collapsing stellar cores. Our initial model consists of a low metallicity rapidly-rotating progenitor which is evolved in axisymmetry with the latest version of our general relativistic code CoCoNuT, which allows for black hole formation and includes the effects of a microphysical equation of state (LS220) and a neutrino leakage scheme to account for radiative losses. The motivation of our study is to analyze in detail the emission of gravitational waves in the collapsar scenario of long gamma-ray bursts. Our simulations show that the phase during which the proto-neutron star (PNS) survives before ultimately collapsing to a black hole is particularly optimal for gravitational wave emission. The high-amplitude waves last for several seconds and show a remarkable quasi-periodicity associated with the violent PNS dynamics, namely during the episodes of convection and the subsequent nonlinear development of the standing-accretion shock instability (SASI). By analyzing the spectrogram of our simulations we are able to identify the frequencies associated with the presence of g-modes and with the SASI motions at the PNS surface. We note that the gravitational waves emitted reach large enough amplitudes to be detected with third-generation detectors as the Einstein Telescope within a Virgo cluster volume at rates ~< 0.1 /y.

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Pablo Cerdá-Durán, Nicolas DeBrye, Miguel A Aloy, José A Font, Martin Obergaulinger. 2013-10-30. Gravitational wave signatures in black-hole-forming core collapse. https://doi.org/10.1088/2041-8205/779/2/l18

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