LIGO Document T2500311-v2

Maximum-Posterior Hyperparameters of the Broken Power Law + 2 Peak Population Model from GWTC-4

Document #:
LIGO-T2500311-v2
Document type:
T - Technical notes
Other Versions:
Abstract:

This document provides the maximum-posterior hyperparameters for the Broken Power Law + 2 Peak (BP2P) population model, inferred from the GWTC-4 catalog (https://dcc.ligo.org/LIGO-P2400004/public). The model describes the primary black hole mass distribution as a broken power-law between minimum and maximum masses,with two Gaussian peaks at \( \sim 10~M_\odot \) and \( \sim 35~M_\odot \). The file includes the posterior values for mass, spin, and merger-rate hyperparameters. These results allow users to reproduce the GWTC-4 population model and to generate synthetic distributions for compact binary coalescences. For additional resources and visualization tools, see: https://cbc-population-distributions.readthedocs.io/en/latest/.

Hyperparameters for the BP2 model are stored in the file:
baseline5_widesigmachi2_mass_NotchFilterBinnedPairingMassDistribution_
redshift_powerlaw_mag_iid_spin_magnitude_gaussian_tilt_iid_spin_orientation_result.hdf5

The file can be easily read by using bilby, see the example:
https://cbc-population-distributions.readthedocs.io/en/latest/guide/setup.html#read-the-hyperparams-file


DCC Version 3.5.2, contact DCC Help