A Frequency-domain Perspective on GW150914 Ringdown Overtone

Yi-Fan Wang (王一帆)^{1, 2, 3}, Collin D. Capano^{4, 2, 3}, Jahed Abedi^{5, 2, 3}, Shilpa Kastha^{6, 2, 3}, Badri Krishnan^{7, 2, 3}, Alex B. Nielsen⁵, Alexander H. Nitz⁸, and Julian Westerweck^{2, 3, 9}

<sub>1. Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Am Mühlenberg 1, D-14476 Potsdam, Germany
2. Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Callinstraße 38, D-30167 Hannover, Germany
3. Leibniz Universität Hannover, D-30167 Hannover, Germany
4. Department of Physics, University of Massachusetts, Dartmouth, MA 02747, USA
5. Department of Mathematics and Physics, University of Stavanger, NO-4036 Stavanger, Norway
6. Niels Bohr International Academy, Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark
7. Institute for Mathematics, Astrophysics and Particle Physics, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
8. Department of Physics, Syracuse University, Syracuse, NY 13244, USA
9. Institute for Gravitational Wave Astronomy and School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom</sub>

Introduction

We revisit the recent debate on the evidence for an overtone in the black hole ringdown of GW150914. By gating and inpainting the data, we discard the contamination from earlier parts of the gravitational wave signal before ringdown. This enables the parameter estimation to be con- ducted in the frequency domain, which is mathematically equivalent to the time domain method. We keep the settings as similar as possible to the previous studies by Cotesta et al. [1] and Isi et al. [2, 3] which yielded conflicting results on the Bayes factor of the overtone. We examine the spectral contents of the matched-filtering in the frequency domain, and propose a convergence test to assess the validity of an overtone model. Our results find the Bayes factors for the overtone fall within 10 and 26 around a range of times centered at the best-fit merger time of GW150914, which supports the existence of an overtone in agreement with the conclusions of Isi et al. [2, 3]. Our work contributes to the understanding of how various methods affect the statistical significance of overtones.

A preprint version of the paper is available on arxiv.

This release contains the posterior files and configuration files for PyCBC Inference. An example to launch a PyCBC Inference run:

OMP_NUM_THREADS=1 \
pycbc_inference --verbose \
    --seed 19930309 \
    --config-file configuration/221/inference-GW150914_srate1024_0.ini \
    --output-file posterior/221/GW150914_SRATE1024_0.hdf \
    --nprocesses 32 \
    --force

License and Citation

This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License.

We encourage use of these data in derivative works. If you use the material provided here, please cite the paper using the reference:

@article{Wang:2023xsy,
    author = "Wang, Yi-Fan and Capano, Collin D. and Abedi, Jahed and Kastha, Shilpa and Krishnan, Badri and Nielsen, Alex B. and Nitz, Alexander H. and Westerweck, Julian",
    title = "{A frequency-domain perspective on GW150914 ringdown overtone}",
    eprint = "2310.19645",
    archivePrefix = "arXiv",
    primaryClass = "gr-qc",
    reportNumber = "LIGO-P2300340",
    month = "10",
    year = "2023"
}