Application of the Hilbert-Huang transform for analyzing standing-accretion-shock-instability induced gravitational waves in a core-collapse supernova. (arXiv:2107.05213v2 [astro-ph.HE] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Takeda_M/0/1/0/all/0/1">M. Takeda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hiranuma_Y/0/1/0/all/0/1">Y. Hiranuma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kanda_N/0/1/0/all/0/1">N. Kanda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kotake_K/0/1/0/all/0/1">K. Kotake</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kuroda_T/0/1/0/all/0/1">T. Kuroda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Negishi_R/0/1/0/all/0/1">R. Negishi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oohara_K/0/1/0/all/0/1">K. Oohara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sakai_K/0/1/0/all/0/1">K. Sakai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sakai_Y/0/1/0/all/0/1">Y. Sakai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sawada_T/0/1/0/all/0/1">T. Sawada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Takahashi_H/0/1/0/all/0/1">H. Takahashi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tsuchida_S/0/1/0/all/0/1">S. Tsuchida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Watanabe_Y/0/1/0/all/0/1">Y. Watanabe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yokozawa_T/0/1/0/all/0/1">T. Yokozawa</a>
Through numerical simulations, it is predicted that the gravitational waves
(GWs) reflect the characteristics of the core-collapse supernova (CCSN)
explosion mechanism. There are multiple GW excitation processes that occur
inside a star before its explosion, and it is suggested that the GWs
originating from the CCSN have a mode for each excitation process in terms of
time-frequency representation. Therefore, we propose an application of the
Hilbert-Huang Transform (HHT), which is a high-resolution time-frequency
analysis method, to analyze these GW modes for theoretically probing and
increasing our understanding of the explosion mechanism. The HHT defines
frequency as a function of time, and is not bound by the trade-off between time
and frequency resolutions. In this study, we analyze a gravitational waveform
obtained from a three-dimensional general-relativistic CCSN model that showed a
vigorous activity of the standing-accretion-shock-instability (SASI). We
succeed in extracting the SASI induced GWs with high resolution on a
time-frequency representation using the HHT and we examine their instantaneous
frequencies.
Through numerical simulations, it is predicted that the gravitational waves
(GWs) reflect the characteristics of the core-collapse supernova (CCSN)
explosion mechanism. There are multiple GW excitation processes that occur
inside a star before its explosion, and it is suggested that the GWs
originating from the CCSN have a mode for each excitation process in terms of
time-frequency representation. Therefore, we propose an application of the
Hilbert-Huang Transform (HHT), which is a high-resolution time-frequency
analysis method, to analyze these GW modes for theoretically probing and
increasing our understanding of the explosion mechanism. The HHT defines
frequency as a function of time, and is not bound by the trade-off between time
and frequency resolutions. In this study, we analyze a gravitational waveform
obtained from a three-dimensional general-relativistic CCSN model that showed a
vigorous activity of the standing-accretion-shock-instability (SASI). We
succeed in extracting the SASI induced GWs with high resolution on a
time-frequency representation using the HHT and we examine their instantaneous
frequencies.
http://arxiv.org/icons/sfx.gif
