Code and data for: Lower Your Rates: On Claims of a Binary Black Hole Merger-Rate Crisis

This repository contains the data, plotting code, and figures used to produce
all results and figures in Broekgaarden (2026), "Lower Your Rates: On Claims
of a Binary Black Hole Merger-Rate Crisis."

The paper compiles and updates local merger-rate predictions (z ≈ 0,
in Gpc⁻³ yr⁻¹) for binary black holes (BH-BH), neutron star–black holes
(NS-BH), and binary neutron stars (NS-NS) from 72 isolated binary-evolution
studies published between 2010 and 2026, comprising 4194 individual submodel
realizations. These are compared to observational constraints from the
LIGO–Virgo–KAGRA Collaboration (GWTC-2 through GWTC-5). The compilation is
used to assess recent claims of a universal tension between isolated binary
evolution and the observed local BBH merger rate.

The repository is organized into three directories:

data/ — CSV rate catalogs for nine formation channels (isolated binary
evolution, chemically homogeneous evolution, globular clusters, nuclear
clusters, young stellar clusters, triples, flybys, Population III stars,
and primordial black holes), plus observational constraints from
gravitational-wave detections, kilonovae, Galactic pulsars, and short GRBs.
The main catalog (isolated-binary-evolution.csv) contains ~4500 rows, one per
study/submodel prediction, with columns for compact object type, code,
merger-rate density, and physics-assumption parameters (alpha_CE, sigma_kick,
beta_MT, lambda_CE, remnant mass prescription, stellar tracks, etc.). A
companion relationships table (isolated-binary-evolution_relationships.csv)
encodes pairwise single-parameter-variation connections between submodels and
drives the interactive merger-rate table. Raw per-study extracted data and
ingestion scripts are in data/individual_extracted_data/.

plotting_code/ — Python scripts and a Jupyter notebook
(Make_figures_COC_rates.ipynb) that reproduce all paper figures and the
interactive merger-rate table from the CSV catalogs. Key modules include
plot_rates.py (matplotlib rate and CDF/violin plots), make_interactive_figures.py
(Plotly interactive rate plots), and merger_rate_table.py (interactive HTML
table with filtering by DCO type, parameter family, and rate limit).

figures/ — Generated PDF/PNG figures and standalone interactive HTML outputs,
including the interactive merger-rate table (merger_rate_table.html).

The supplementary material documenting rate extractions for each study is
provided as lower-your-rates-supplementary_material.pdf.

The interactive online version of the compiled rate table is available at
https://floorbroekgaarden.github.io/lower-your-rates/

For questions or suggestions for additional literature, please contact:
fbroekgaarden@ucsd.edu