Black hole genealogy: Identifying hierarchical mergers with gravitational waves
Reviewed by Pith T0 review T1 audit T2 compute T3 formal T4 kernel pith:MK6OLGSTrecord.jsonopen to challenge →
read the original abstract
In dense stellar environments, the merger products of binary black hole mergers may undergo additional mergers. These hierarchical mergers are predicted to have higher masses than the first generation of black holes made from stars. The components of hierarchical mergers are expected to have significant characteristic spins $\chi\sim 0.7$. However, since the population properties of first-generation black holes are uncertain, it is difficult to know if any given merger is first-generation or hierarchical. We use observations of gravitational waves to reconstruct the binary black hole mass and spin spectrum of a population containing hierarchical merger events. We employ a phenomenological model that captures the properties of merging binary black holes from simulations of dense stellar environments. Inspired by recent work on the isolated formation of low-spin black holes, we include a zero-spin subpopulation. We analyze binary black holes from LIGO and Virgo's first two observing runs, and find that this catalog is consistent with having no hierarchical mergers. We find that the most massive system in this catalog, GW170729, is mostly likely a first-generation merger, having a $4\%$ probability of being a hierarchical merger assuming a $5 \times 10^5 M_{\odot}$ globular cluster mass. Using our model, we find that $99\%$ of first-generation black holes in coalescing binaries have masses below 44 $M_{\odot}$, and the fraction of binaries with near-zero spin is $0.051^{+0.156}_{-0.048}$ ($90\%$ credible interval). Upcoming observations will determine if hierarchical mergers are a common source of gravitational waves.
This paper has not been read by Pith yet.
Forward citations
Cited by 6 Pith papers
-
Emergent structure in the binary black hole mass distribution and implications for population-based cosmology
B-spline agnostic reconstruction of binary black hole masses from GWTC-4.0 reveals multiple features and a logarithmic hierarchy that impacts Hubble constant measurements, with a low-mass subpopulation isolation metho...
-
Disentangling spinning and nonspinning binary black hole populations with spin sorting
Spin sorting with the default spin model distinguishes spinning and nonspinning binary black hole populations in simulations and shows real data rule out a fully nonspinning population but allow mixed ones with up to ...
-
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.
-
Effects of formation channels and gravitational lensing on stochastic gravitational wave background
Using HBI on GWTC-4 data the authors compute lensed SGWBs for ABHs and PBHs and conclude that LIGO and ET can distinguish the two formation channels in specific frequency ranges, with ET offering broader coverage.
-
GWTC-2.1: Deep Extended Catalog of Compact Binary Coalescences Observed by LIGO and Virgo During the First Half of the Third Observing Run
GWTC-2.1 adds eight new high-significance compact binary coalescence events to the prior catalog, extending the observed black hole mass range and including candidates inside the pair-instability mass gap.
-
Bayesian inference for compact binary coalescences with BILBY: Validation and application to the first LIGO--Virgo gravitational-wave transient catalogue
BILBY is validated on simulated compact binary signals and reproduces the eleven GWTC-1 results with configuration and output files provided for reproduction.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.