Supernova seismology: Gravitational wave signatures of rapidly rotating core collapse

Jim Fuller, Hannah Klion, Ernazar Abdikamalov, Christian D. Ott

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Gravitational waves (GW) generated during a core-collapse supernova open a window into the heart of the explosion. At core bounce, progenitors with rapid core rotation rates exhibit a characteristic GW signal which can be used to constrain the properties of the core of the progenitor star. We investigate the dynamics of rapidly rotating core collapse, focusing on hydrodynamic waves generated by the core bounce, and the GW spectrum they produce. The centrifugal distortion of the rapidly rotating proto-neutron star (PNS) leads to the generation of axisymmetric quadrupolar oscillations within the PNS and surrounding envelope. Using linear perturbation theory, we estimate the frequencies, amplitudes, damping times, and GW spectra of the oscillations. Our analysis provides a qualitative explanation for several features of the GW spectrum and shows reasonable agreement with non-linear hydrodynamic simulations, although a few discrepancies due to non-linear/rotational effects are evident. The dominant early post-bounce GW signal is produced by the fundamental quadrupolar oscillation mode of the PNS, at a frequency 0.70 ≲ f ≲ 0.80 kHz, whose energy is largely trapped within the PNS and leaks out on a ~10-ms time-scale. Quasi-radial oscillations are not trapped within the PNS and quickly propagate outwards until they steepen into shocks. Both the PNS structure and Coriolis/centrifugal forces have a strong impact on the GW spectrum, and a detection of the GW signal can therefore be used to constrain progenitor properties.

Original languageEnglish
Pages (from-to)414-427
Number of pages14
JournalMonthly Notices of the Royal Astronomical Society
Volume450
Issue number1
DOIs
Publication statusPublished - Mar 27 2015

Keywords

  • Gravitational waves
  • Hydrodynamics
  • Stars: oscillations
  • Stars: rotation
  • Supernovae: general
  • Waves

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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