Seeking Spinning Subpopulations of Black Hole Binaries via Iterative Density Estimation

Abstract

Attempts to understand the formation of binary black hole (BBH) systems detected via gravitational wave (GW) emission are affected by many unknowns and uncertainties, from both the observational and theoretical (astrophysical modelling) sides. Binary component spins have been proposed as a means to investigate formation channels, however obtaining clear inferences is challenging, given the apparently low magnitude of almost all merging BH spins and their high measurement uncertainties. Even for the effective aligned spin ${\chi }_{\mathrm{eff}}$ which is more precisely measured than component spins, specific model assumptions have been required to identify any clear trends. Here, we reconstruct the joint component mass and ${\chi }_{\mathrm{eff}}$ distribution of BBH mergers with minimal assumptions using the GWTC-3 catalog, using an iterative kernel density estimation (KDE)-based method. We reproduce some features seen in previous analyses, for instance a small but preferentially positive ${\chi }_{\mathrm{eff}}$ for low-mass mergers; we also identify a possible subpopulation of higher-spin BBH with $|{\chi }_{\mathrm{eff}}|$ up to $\sim 0.75$ for primary masses $m_1\gtrsim 40M_{\odot }$, in addition to the bulk of the distribution with $|{\chi }_{\mathrm{eff}}|\lesssim 0.2$. This finding is consistent with previous studies indicating a broader spin distribution at high mass, suggesting a distinct origin for the high-spin systems. We also identify a new potential trend of low-mass BBHs: the \emph{derivative} of ${\chi }_{\mathrm{eff}}$ with respect to $m_1$ ($m_2$) is positive (negative) over the $10$--$15M_{\odot }$ range. This apparent structure may be related to} a previously reported anticorrelation between mass ratio and ${\chi }_{\mathrm{eff}}$.

12 pages, 8figures Version 2:Edited and update; Accepted for publication in Physical Review D

References in corpus (42)

• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Advanced LIGO
• GW190814: Gravitational Waves from the Coalescence of a 23 M${}_{\odot }$ Black Hole with a 2.6 M${}_{\odot }$ Compact Object
• GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run
• GW190521: A Binary Black Hole Merger with a Total Mass of $150M_{\odot }$
• Robust parameter estimation for compact binaries with ground-based gravitational-wave observations using the LALInference software library
• Illuminating Black Hole Binary Formation Channels with Spins in Advanced LIGO
• One Channel to Rule Them All? Constraining the Origins of Binary Black Holes using Multiple Formation Pathways
• Lidov-Kozai Cycles with Gravitational Radiation: Merging Black Holes in Isolated Triple Systems
• Distinguishing Spin-Aligned and Isotropic Black Hole Populations With Gravitational Waves
• The final mass and spin of black hole mergers
• The redshift evolution of the binary black hole merger rate: a weighty matter
• Cover Your Basis: Comprehensive Data-Driven Characterization of the Binary Black Hole Population
• Binary black hole mergers: formation and populations
• No peaks without valleys: The stable mass transfer channel for gravitational-wave sources in light of the neutron star-black hole mass gap
• The spins of compact objects born from helium stars in binary systems
• Exploring Features in the Binary Black Hole Population
• Coalescing black hole binaries from globular clusters: mass distributions and comparison to gravitational wave data from GWTC-3
• A Parameter-Free Tour of the Binary Black Hole Population
• Suspicious Siblings: The Distribution of Mass and Spin Across Component Black Holes in Isolated Binary Evolution
• Resolving the Stellar-Collapse and Hierarchical-Merger origins of the Coalescing Black Holes
• Signatures of mass ratio reversal in gravitational waves from merging binary black holes
• Searching for mass-spin correlations in the population of gravitational-wave events: the GWTC-3 case study
• Flexible and Fast Estimation of Binary Merger Population Distributions with Adaptive KDE
• What You Don't Know Can Hurt You: Use and Abuse of Astrophysical Models in Gravitational-wave Population Analyses
• Evidence for a correlation between binary black hole mass ratio and black-hole spins
• Tidal Spin-up of Black Hole Progenitor Stars
• The ${\chi }_{\mathrm{eff}}-z$ correlation of field binary black hole mergers and how 3G gravitational-wave detectors can constrain it
• Unequal-mass, highly-spinning binary black hole mergers in the stable mass transfer formation channel
• Dropping Anchor: Understanding the Populations of Binary Black Holes with Random and Aligned Spin Orientations
• Is there an excess of black holes around $20M_{\odot }$? Optimising the complexity of population models with the use of reversible jump MCMC
• Model exploration in gravitational-wave astronomy with the maximum population likelihood
• Binary vision: The merging black hole binary mass distribution via iterative density estimation
• PixelPop: High Resolution Nonparameteric Inference of Gravitational-Wave Populations in Multiple Dimensions
• Nonparametric analysis of correlations in the binary black hole population with LIGO-Virgo-KAGRA data
• Unmodelled Clustering Methods for Gravitational Wave Populations of Compact Binary Mergers
• Spin Doctors: How to diagnose a hierarchical merger origin
• Exploring field-evolution and dynamical-capture coalescing binary black holes in GWTC-3
• Compactness peaks: An astrophysical interpretation of the mass distribution of merging binary black holes
• Reconstructing parametric gravitational-wave population fits from non-parametric results without refitting the data
• Reconstructing the LISA massive black hole binary population via iterative kernel density estimation
• Looking To The Horizon: Probing Evolution in the Black Hole Spectrum With Gravitational Wave Catalogs

Cited by in corpus (1)

• Reducing systematic uncertainties in gravitational-wave population analyses by increasing the detection threshold