Hierarchical Bayesian analysis of GWTC-5.0 data identifies a mass transition at 15.2 solar masses separating distinct effective-spin distributions, pointing to different formation channels for low-mass binary black holes.
Compactness Peaks and Subpopulations: Probing Stellar Physics and Formation Channels of Merging Binary Black Holes
6 Pith papers cite this work. Polarity classification is still indexing.
abstract
The growing catalog of gravitational-wave detections from the LIGO-Virgo-KAGRA (LVK) collaboration reveals structure in the binary black hole (BBH) mass distribution, including peaks near m1 = 10 solar masses and m1 = 35 solar masses, a high-mass suppression consistent with the pair-instability supernova gap, and a possible dearth of systems near chirp mass M = 10-12 solar masses. We apply Compactness Peaks + Channels, a stripped-star-motivated five-component population model, to 152 BBH mergers from GWTC-4.0. The model is decisively preferred over the LVK Broken Power Law + 2 Peaks baseline, with log10 Bayes factor = 7.69, and decomposes the population into isolated first-generation (1G), dynamical 1G, and hierarchical second-generation (2G) channels with fractions 0.75 (+0.11/-0.16), 0.22 (+0.16/-0.11), and 0.02 (+0.03/-0.01), respectively. The low-mass isolated component sharply localizes the 10 solar mass feature, with narrow masses, near-equal mass ratios, and low partially aligned spins, consistent with stripped-star binary evolution. The 35 solar mass feature is primarily captured by the high-mass dynamical 1G component. The hierarchical component is consistent with 2G+1G mergers, with elevated primary spins, mu_chi = 0.65 (+0.30/-0.22), and asymmetric mass ratios. We localize the compactness-peak edges at 12.3 (+2.4/-1.3) and 16.1 (+5.7/-5.3) solar masses, consistent with, but not yet requiring, a compactness-driven dearth between them. These results support a multi-component description of the BBH population and motivate further tests of compactness-driven isolated evolution.
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Joint strong-lensing and population inference on resolved gravitational-wave events finds no lensed events and tightens constraints on the black-hole merger rate peak redshift and high-redshift tail.
The chirp-mass distribution of GW-detected binary black holes shows a ladder of peaks doubling in mass, with a new intermediate peak at 19 solar masses confirming a prior prediction from the hierarchical merger model.
Non-parametric analysis of GWTC-5.0 data supports multiple subpopulations of binary black holes distinguished by effective spin, with one aligned subpopulation suggesting dynamical formation.
GWTC-5.0 analysis finds evidence for structure beyond a non-skewed Gaussian bulk in χ_eff, with suggestive mass-dependent excess of positive over negative spins outside the bulk at 13:1 odds in one mass bin.
A review summarizing formation-channel predictions, waveform effects, and population-level constraints on stellar-mass black hole spins from the first decade of gravitational-wave observations.
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Distinct spin properties and astrophysical origin of low mass binary black holes in gravitational wave data
Hierarchical Bayesian analysis of GWTC-5.0 data identifies a mass transition at 15.2 solar masses separating distinct effective-spin distributions, pointing to different formation channels for low-mass binary black holes.
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Joint population and strong-lensing inference for resolved gravitational-wave events probes the black-hole merger rate beyond the peak of star formation
Joint strong-lensing and population inference on resolved gravitational-wave events finds no lensed events and tightens constraints on the black-hole merger rate peak redshift and high-redshift tail.
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The Chirp-Mass Ladder: A New Rung Emerges
The chirp-mass distribution of GW-detected binary black holes shows a ladder of peaks doubling in mass, with a new intermediate peak at 19 solar masses confirming a prior prediction from the hierarchical merger model.
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When the black holes align: a subpopulation of aligned massive binary black holes observed via gravitational waves
Non-parametric analysis of GWTC-5.0 data supports multiple subpopulations of binary black holes distinguished by effective spin, with one aligned subpopulation suggesting dynamical formation.
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Evidence for additional structure in the effective spin distribution hints at multiple formation pathways in GWTC-5.0
GWTC-5.0 analysis finds evidence for structure beyond a non-skewed Gaussian bulk in χ_eff, with suggestive mass-dependent excess of positive over negative spins outside the bulk at 13:1 odds in one mass bin.
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The first decade of gravitational-wave measurements of black hole spins
A review summarizing formation-channel predictions, waveform effects, and population-level constraints on stellar-mass black hole spins from the first decade of gravitational-wave observations.