Analysis of the subsolar-mass black hole candidate SSM200308 from the second part of the third observing run of Advanced LIGO-Virgo

• Published in: arXiv.org
• Main Authors: Prunier, Marine, Morrás, Gonzalo, Nuño Siles, José Francisco, Clesse, Sebastien, García-Bellido, Juan, Ester Ruiz Morales
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 23.09.2024
• Subjects: Binary stars; Black holes; False alarms; Gravitational waves; Neutron stars; Parameter estimation; Physics - Cosmology and Nongalactic Astrophysics; Physics - General Relativity and Quantum Cosmology; Signal to noise ratio
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2311.16085

A follow-up of a subsolar black hole candidate identified in the second part of the third observing run of the LIGO-Virgo-KAGRA collaboration is carried out. With a search signal-to-noise ratio of \(8.90\) and a false-alarm rate of 1 per 5 years, close to the usual thresholds for claiming a gravitational-wave event, we cannot exclude a noise origin. A complete Bayesian parameter estimation of this candidate, denoted SSM200308, reveals that if the signal originates from a compact binary coalescence, the component masses are \(m_1= 0.62^{+0.46}_{-0.20} M_{\odot}\) and \(m_2 = 0.27^{+0.12}_{-0.10} M_{\odot}\) (90% credible intervals) with at least one component being firmly subsolar, below the minimum mass of a neutron star. This discards the hypothesis that the signal comes from a standard binary neutron star. The signal coherence test between the two LIGO detectors brings support to a compact object coalescence origin.