A Linear and Quadratic Time-Frequency Analysis of Gravitational Waves from Core-Collapse Supernovae

Abstract

Recent core-collapse supernova (CCSN) simulations have predicted several distinct features in gravitational-wave (GW) spectrograms, including a ramp-up signature due to the g-mode oscillation of the proto-neutron star (PNS) and an excess in the low-frequency domain (100-300 Hz) potentially induced by the standing accretion shock instability (SASI). These predictions motivated us to perform a sophisticated time-frequency analysis (TFA) of the GW signals, aimed at preparation for future observations. By reanalyzing a gravitational waveform obtained in a three-dimensional general-relativistic CCSN simulation, we show that both the spectrogram with an adequate window and the quadratic TFA separate the multimodal GW signatures much more clearly compared with the previous analysis. We find that the observed low-frequency excess during the SASI active phase is divided into two components, a stronger one at 130 Hz and an overtone at 260 Hz, both of which evolve quasi-statically during the simulation time. We also identify a new mode whose frequency varies from 700 to 600 Hz. Furthermore, we develop the quadratic TFA for the Stokes I, Q, U, and V parameters as a new tool to investigate the GW circular polarization. We demonstrate that the polarization states that randomly change with time after bounce are associated with the PNS g-mode oscillation, whereas a slowly changing polarization state in the low-frequency domain is connected to the PNS core oscillation. This study demonstrates the capability of the sophisticated TFA for diagnosing the polarized CCSN GWs in order to explore their complex nature.

14 pages,18 figures. Accepted for publication in ApJ. The code for the time-frequency analysis used in the paper is available here: https://github.com/HajimeKawahara/juwvid

References in corpus (12)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence
• The gravitational wave burst signal from core collapse of rotating stars
• The gravitational wave signal from core-collapse supernovae
• Rotation-supported Neutrino-driven Supernova Explosions in Three Dimensions and the Critical Luminosity Condition
• Measuring a Parity Violation Signature in the Early Universe via Ground-based Laser Interferometers
• Correlated Signatures of Gravitational-Wave and Neutrino Emission in Three-Dimensional General-Relativistic Core-Collapse Supernova Simulations
• Equation of State Dependent Dynamics and Multimessenger Signals from Stellar-mass Black Hole Formation
• Probing mass-radius relation of protoneutron stars from gravitational-wave asteroseismology
• Nonlinear Saturation of g-modes in Proto-Neutron Stars: Quieting the Acoustic Engine
• Circular polarization of gravitational waves from non-rotating supernova cores: a new probe into the pre-explosion hydrodynamics
• The g-mode Excitation in the Proto Neutron Star by the Standing Accretion Shock Instability

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