DOI: 10.5281/zenodo.14691458
title: Data release: Searching for binary black hole sub-populations in gravitational wave data using binned Gaussian processes

description: The data required to reproduce the analyses of "Searching for binary black hole sub-populations in gravitational wave data using binned Gaussian processes" (arxiv:2404.03166). The main inference code can be found at https://github.com/AnaryaRay1/gppop/tree/spin-dev  (commit: ee5ffc). To reproduce the analyses, follow the instructions at https://github.com/AnaryaRay1/bbh-subpopulations-scripts (commit de88f93). Frozen versions of these repositories that were used to generate all the results are available as part of this data release, in the files "gppop_spin_dev_ee5ffc421.tar.gz" and "bbh-subpopulations-scripts_de88f931.tar.gz" respectively.
description: Astrophysically motivated population models for binary black hole observables are often insufficient to capture the imprints of multiple formation channels. This is mainly due to the strongly parametrized nature of such investigations. Using a non-parametric model for the joint population-level distributions of binary black hole component masses and effective inspiral spins, we find hints of multiple subpopulations in the third gravitational wave transient catalog. The higher (more positive) spin subpopulation is found to have a mass-spectrum without any feature at the $30-40M_{\odot}$, which is consistent with the predictions of isolated stellar binary evolution, simulations for which place the pile up due to pulsational pair-instability supernovae near $50M_{\odot}$ or higher. The other sub-population with effective spins closer to zero shows a feature at $30-40M_{\odot}$ and is consistent with binary black holes formed dynamically in globular clusters, which are expected to peak around $30M_{\odot}$. We also compute merger rates for these two subpopulations and find that they are consistent with the theoretical predictions of the corresponding formation channels. We validate our results by checking their robustness against variations of several model configurations and by analyzing large simulated catalogs with the same model.
description: Reproducing Figure 1 and Figures 5-9 (Real events)

GWTC-1, GWTC-2, and GWTC-3 significant catalog parameter estimation (PE) samples are needed along with the O1+O2+O3 sensitivity estimate injections, which are all available in the file named gwtc3_data.tar.gz. Also necessary for the comparison plots are the population inference results conducted by the LVK for GWTC-3. These are available in the file named gwtc3_lvk_pop_results.tar.gz.

These files were downloaded and renamed from the following public data realeses by the LVC and the LVK:

[1] LVC (2019), Parameter estimation sample release for GWTC-1, doi:10.7935/KSX7-QQ51

[2] LVC (2020), GWTC-2 Data Release: Parameter Estimation Samples and Skymaps, URL: https://dcc.ligo.org/LIGO-P2000223/public/LVK (2023): GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run — Parameter estimation data release, URL: https://zenodo.org/records/8177023 (Note, the files named *_ncosmo.hdf5 were downloaded)

[3] LVK (2023): GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run — O1+O2+O3 Search Sensitivity Estimates. URL: https://zenodo.org/records/7890398 (Note: the file named "o1+o2+o3_bbhpop_real+semianalytic-LIGO-T2100377-v2.hdf5" was downloaded) 

[4] LVK (2023), The population of merging compact binaries inferred using gravitational waves through GWTC-3 - Data release, https://doi.org/10.5281/zenodo.5655785 (Note: the files GWTC-3-population-data.tar.gz/analyses/PowerLawPeak/o1o2o3_mass_c_iid_mag_iid_tilt_powerlaw_redshift_result.json and GWTC-3-population-data.tar.gz/analyses/PowerLawPeak/o1o2o3_mass_c_iid_mag_iid_tilt_powerlaw_redshift_result.json were downloaded)

 

Reproducing Figures 2 and 3 (Simulated data)

PE samples for simulated events for 5 different populations are uploaded in this record (generated using code available in https://github.com/AnaryaRay1/bbh-subpopulations-scripts/tree/main/generate_simulations_example):

Simulations drawn from an uncorrelated population are available in: sims_uncorrelated.tar.gz

Simulations drawn from a population with redshift and effective inspiral spin correlation are available in: sims_z_chieff_correlated.tar.gz

Simulations drawn from a population with mass ratio and effective inspiral spin correlation are available in: sims_q_chieff_correlated.tar.gz

Simulations drawn from a population wherein the 30 solar mass peak is associated with a positively skewed effective inspiral spin distribution are available in: sims_peak+aligned.tar.gz

Simulations drawn from a population wherein the 30 solar mass peak is associated with a symmetric effective inspiral spin distribution are available in: sims_peak+isotropic.tar.gz

 

Sensitivity injections for O3 and the O3 noise PSDs used to generate the simulations and conduct their parameter estimation are available in o3_sensitivity_injections_psd.tar.gz . These were obtained from LVK's public data releases:

[5] LVK (2023): GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run — O3 search sensitivity estimates. URL: https://zenodo.org/records/789039 (Note: the file named "endo3_bbhpop-LIGO-T2100113-v12.hdf5" was downloaded).

[6] LVK (2022): Noise curves used for Simulations in the update of the Observing Scenarios Paper, (Note, the files named *_sensitivity (based on first three months of O3).txt   were downloaded).