Year: 2022
Type: article
Abstract: We reanalyze the GW150914 postmerger data searching for quasinormal modes beyond the fundamental, quadrupolar mode. There is currently an ongoing disagreement in the literature about whether, and to what extent, the data contains evidence for a quasinormal mode overtone. We use a frequency-domain approach to ringdown data analysis that was recently proposed by the authors. Our analysis has several advantages compared to other analyses performed mainly in the time domain; in particular, the source sky position and the ringdown start time are marginalized over (as opposed to simply being fixed) as part of a Bayesian ringdown analysis. We find tentative evidence for an overtone in GW150914, but at a lower significance than reported elsewhere. Our preferred analysis, marginalizing over the uncertainty in the time of peak strain amplitude, gives a posterior on the overtone amplitude peaked away from zero at $\ensuremath{\sim}1.8\ensuremath{\sigma}$.
Authors: Eliot Finch, Christopher J. Moore
Institution: University of Birmingham
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, Flatiron Health, National Research Foundation, Ministry of Education, Culture, Sports, Science and Technology, Academia Sinica, Ministry of Science and Technology, Taiwan, Centre National de la Recherche Scientifique, Istituto Nazionale di Fisica Nucleare, Ministry of Science and ICT, South Korea, Science and Technology Facilities Council, Japan Society for the Promotion of Science
Awards: G1961815585, G6872471089
OpenAlex ID: W4280532841