A follow-up on intermediate-mass black hole candidates in the second LIGO–Virgo observing run with the Bayes Coherence Ratio

• Published in: Monthly notices of the Royal Astronomical Society Vol. 516; no. 4; pp. 5309 - 5317
• Main Authors: Vajpeyi, Avi, Smith, Rory, Thrane, Eric, Ashton, Gregory, Alford, Thomas, Garza, Sierra, Isi, Maximiliano, Kanner, Jonah, Massinger, T J, Xiao, Liting
• Format: Journal Article
• Language: English
• Published: Oxford University Press 28.09.2022
• Subjects: black hole mergers; methods: statistical; gravitational waves; methods: data analysis
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stac2332

ABSTRACT The detection of an intermediate-mass black hole population (102–106 M⊙) will provide clues to their formation environments (e.g. discs of active galactic nuclei, globular clusters) and illuminate a potential pathway to produce supermassive black holes. Ground-based gravitational-wave detectors are sensitive to mergers that can form intermediate-mass black holes weighing up to ∼450 M⊙. However, ground-based detector data contain numerous incoherent short duration noise transients that can mimic the gravitational-wave signals from merging intermediate-mass black holes, limiting the sensitivity of searches. Here, we follow-up on binary black hole merger candidates using a ranking statistic that measures the coherence or incoherence of triggers in multiple-detector data. We use this statistic to rank candidate events, initially identified by all-sky search pipelines, with lab-frame total masses ≳ 55 M⊙ using data from LIGO’s second observing run. Our analysis does not yield evidence for new intermediate-mass black holes. However, we find support for eight stellar-mass binary black holes not reported in the first LIGO–Virgo gravitational wave transient catalogue GWTC-1, seven of which have been previously reported by other catalogues.