Physics & Astronomy Faculty Publications
Document Type
Article
Publication Date
10-27-2025
Abstract
On 2023 November 23 the two LIGO observatories both detected GW231123, a gravitational-wave signal consistent with the merger of two black holes with masses and (90\% credible intervals), at luminosity distance 0.7-4.1 Gpc and redshift of , and a network signal-to-noise ratio of 20.7. Both black holes exhibit high spins, and respectively. A massive black hole remnant is supported by an independent ringdown analysis. Some properties of GW231123 are subject to large systematic uncertainties, as indicated by differences in inferred parameters between signal models. The primary black hole lies within or above the theorized mass gap where black holes between 60-130 should be rare due to pair instability mechanisms, while the secondary spans the gap. The observation of GW231123 therefore suggests the formation of black holes from channels beyond standard stellar collapse, and that intermediate-mass black holes of mass 200 form through gravitational-wave driven mergers.
Recommended Citation
Al-Shammari, Sama, Oshadha Amarasinghege, Fabio Bergamin, Divyajyoti Divyajyoti, Katherine L. Dooley, Stephen Fairhurst, A. S. Goettel et al. "GW231123: A binary black hole merger with total mass 190–265 M⊙." The Astrophysical Journal Letters 993, no. 1 (2025). https://doi.org/10.3847/2041-8213/ae0c9c
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Publication Title
The Astrophysical Journal Letters
DOI
10.3847/2041-8213/ae0c9c
Comments
© 2025. The Author(s). Published by the American Astronomical Society.
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.