Bilby: A User-friendly Bayesian Inference Library for Gravitational-wave Astronomy

Gregory Ashton, Moritz Hübner, Paul D. Lasky, Colm Talbot, Kendall Ackley, Sylvia Biscoveanu, Qi Chu, Atul Divakarla, Paul J. Easter, Boris Goncharov, Francisco Hernandez Vivanco, Jan Harms, Marcus E. Lower, Grant D. Meadors, Denyz Melchor, Ethan Payne, Matthew D. Pitkin, Jade Powell, Nikhil Sarin, Rory J.E. SmithEric Thrane

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24 Citations (Scopus)


Bayesian parameter estimation is fast becoming the language of gravitational-wave astronomy. It is the method by which gravitational-wave data is used to infer the sources' astrophysical properties. We introduce a user-friendly Bayesian inference library for gravitational-wave astronomy, Bilby. This Python code provides expert-level parameter estimation infrastructure with straightforward syntax and tools that facilitate use by beginners. It allows users to perform accurate and reliable gravitational-wave parameter estimation on both real, freely available data from LIGO/Virgo and simulated data. We provide a suite of examples for the analysis of compact binary mergers and other types of signal models, including supernovae and the remnants of binary neutron star mergers. These examples illustrate how to change the signal model, implement new likelihood functions, and add new detectors. Bilby has additional functionality to do population studies using hierarchical Bayesian modeling. We provide an example in which we infer the shape of the black hole mass distribution from an ensemble of observations of binary black hole mergers.

Original languageEnglish
Article number27
Number of pages13
JournalThe Astrophysical Journal Supplement Series
Issue number2
Publication statusPublished - 1 Apr 2019


  • gravitational waves
  • methods: data analysis
  • methods: statistical
  • stars: black holes
  • stars: neutron

Cite this

Ashton, G., Hübner, M., Lasky, P. D., Talbot, C., Ackley, K., Biscoveanu, S., Chu, Q., Divakarla, A., Easter, P. J., Goncharov, B., Vivanco, F. H., Harms, J., Lower, M. E., Meadors, G. D., Melchor, D., Payne, E., Pitkin, M. D., Powell, J., Sarin, N., ... Thrane, E. (2019). Bilby: A User-friendly Bayesian Inference Library for Gravitational-wave Astronomy. The Astrophysical Journal Supplement Series, 241(2), [27].