2025-07-22 コロンビア大学
＜関連情報＞
- https://news.columbia.edu/news/gravitational-waves-reveal-most-massive-black-hole-merger-ever-detected
- https://arxiv.org/abs/2507.08219
GW231123：総質量190-265 M⊙の二重ブラックホール合体 GW231123: a Binary Black Hole Merger with Total Mass 190-265 M⊙
The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration
arXiv Submitted on 10 Jul 2025
DOI:https://doi.org/10.48550/arXiv.2507.08219
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 137+22 −17 M⊙ and 103+20 −52 M⊙ (90% credible intervals), at luminosity distance 0.7–4.1 Gpc and redshift of 0.39+0.27 −0.24, and a network signalto-noise ratio of ∼22.5. Both black holes exhibit high spins, 0.90+0.10 −0.19 and 0.80+0.20 −0.51 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 M⊙ 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 M⊙ form through gravitational-wave driven mergers.
