When the black holes align: a subpopulation of aligned massive binary black holes observed via gravitational waves

arXiv:2606.23305 · astro-ph.HE · Submitted 2026-06-22 · Read on arXiv

astro-ph.HE

Submitted: 2026-06-22

Updated: 2026-09-14

Comments: 9 pages, 6 figures. Resubmitted after implementing referee's comments

License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

Terminology

• AGN — 25× in this paper · explained in 1 episode
• Alignment — 4× in this paper · explained in 1 episode
• Chinese University of Hong Kong — 3× in this paper
• Academia Sinica — 1× in this paper
• Activation Function — 1× in this paper · explained in 1 episode
• Anti-correlation — 1× in this paper · explained in 3 episodes
• Degeneracy — 1× in this paper · explained in 3 episodes
• Markov Chain Monte Carlo — 1× in this paper
• Metallicity — 1× in this paper · explained in 3 episodes

Sources

• GWTC-4.0: Population Properties of Merging Compact Binaries
• Evidence for additional structure in the effective spin distribution hints at multiple formation pathways in GWTC-5.0
• Evidence for Three Subpopulations of Merging Binary Black Holes at Different Primary Masses
• The first decade of gravitational-wave measurements of black hole spins
• Transitions in the Mass-ratio and Spin Properties of Binary Black Holes in GWTC-5
• Compactness Peaks and Subpopulations: Probing Stellar Physics and Formation Channels of Merging Binary Black Holes
• Evidence for mass-dependent spin subpopulations in GWTC-4
• Modern tidal interaction models for rapid binary population synthesis: II. Binary black hole formation, mergers, and spins
• Aligned Hierarchical Black Hole Mergers in Active-Galactic-Nuclei Disks Revealed by GWTC-4
• BBH-Genesis: Disentangling Binary Black Hole Formation Channels with GWTC-4
• Signatures of a subpopulation of hierarchical mergers in the GWTC-4 gravitational-wave dataset
• Reversible-jump MCMC reveals binary black hole subpopulations with distinct redshift evolution
• GWTC-5.0: Observations from the Second Part of the Fourth LIGO-Virgo-KAGRA Observing Run and Updates to the Gravitational-Wave Transient Catalog
• GWTC-5.0: Population Properties of Merging Compact Binaries
• Open Data from LIGO, Virgo, and KAGRA through the Second Part of the Fourth Observing Run
• AGN-driven BBH mergers: Black hole populations and hierarchical growth across the AGN parameter space
• Mass and effective spin distributions of binary black hole events: Evidence for a population of hierarchical black hole mergers in active galactic nuclei disks

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