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GWTC Analysis

GWTC Analysis (gwtc_analysis) is a command-line suite for exploring the public Gravitational-Wave Transient Catalogs (GWTC) of the LIGO–Virgo–KAGRA (LVK) collaboration, from GWTC-1 (2015) to GWTC-5.0 (the O4b observing run, 2025).

Catalogs in version 0.6.1: GWTC-1, GWTC-2.1, GWTC-3, GWTC-4.0, GWTC-5.0, and the update GWTC-4.1 (of GWTC-4.0), observing runs O1 to O4b. Latest catalog: GWTC-5.0 (O4b). Registry checked against GWOSC and Zenodo on 2026-10-01; catalogs published later need a newer version of the package (gwtc_analysis check_catalogs tells whether GWOSC has published one).

It reads the catalogs directly from their public releases (GWOSC, Zenodo, an S3 mirror or Galaxy collections) and produces TSV tables, plots and self-contained HTML reports.

What it does

Mode Purpose
catalog_statistics Catalog-wide tables and plots: masses, distances, SNR, detector networks, sky-localization areas, remnants (radiated energy, final spin)
event_selection Events selected by mass, distance and χ_eff ranges, or by class: neutron stars, lower mass gap, hierarchical-merger candidates
search_skymaps Events whose sky localization contains a given sky position
parameters_estimation Posterior plots of one event, whitened strain overlays, q-transforms, matched-filter SNR
build_unofficial_pe A PESummary-compatible bundle for GW170817, rebuilt from public GWTC-1 products
rates BNS, NSBH and BBH merger rates, R = N / ⟨VT⟩, from the catalogs and the LVK sensitivity injections
hubble_constant The Hubble constant from the binary-black-hole mass spectrum (spectral siren), with icarogw
bright_siren The Hubble constant from an event with an identified host (bright siren): GW170817 and NGC 4993, or the candidate GW190521 flare; alone or combined with the spectral siren
zenodo_releases The versions of the Zenodo catalog releases (Data sources)

Highlights

  • Hubble constant from black holes alone. The hubble_constant mode reproduces the Power Law + Peak spectral-siren measurement of the GWTC-4.0 cosmology paper [29]: H₀ = 105.8 (+44.7 / −33.2) km/s/Mpc against the published 105.5 (+46.4 / −35.8), with the same 137 binary black holes, PE samples, injections and priors. See Hubble constant (spectral siren).
  • Merger rates of the three source classes, corrected for selection effects with the LVK search-sensitivity injections. See Merger rates.
  • Robust access to the releases: Zenodo versions resolved at run time, and missing PSDs of official releases filled from the events' discovery releases. See Known issues in the public releases.

Primary masses of the confident GW events

Where to go next

The source code is on GitHub under the MIT license.