Compact Object Mergers: Population Astrophysics & Statistics

COMPAS is a publicly available rapid binary population synthesis code (https://compas.science/) that is designed so that evolution prescriptions and model parameters are easily adjustable. COMPAS draws properties for a binary star system from a set of initial distributions, and evolves it from zero-age main sequence to the end of its life as two compact remnants. It has been used for inference from observations of gravitational-wave mergers, Galactic neutron stars, X-ray binaries, and luminous red novae.

Documentation

https://compas.science/docs

Contact

Please email your queries to compas-user@googlegroups.com. You are also welcome to join the COMPAS User Google Group to engage in discussions with COMPAS users and developers.

Acknowledgements

If you use this code or parts of this code for results presented in a scientific publication, we would greatly appreciate if you send us your paper reference and make your input settings and output data publicly available by uploading it to the COMPAS Zenodo community. Please also kindly include citations to our COMPAS methods papers https://ui.adsabs.harvard.edu/abs/2022ApJS..258...34R and https://ui.adsabs.harvard.edu/abs/2025ApJS..280...43T . As the public COMPAS code is a product of work by the entire COMPAS collaboration over many years, we kindly request that, in recognition of this team effort, the papers are cited as “Team COMPAS: J. Riley et al. (2021)” and "Team COMPAS: I. Mandel et al. (2025). Example bibtex codes are:

@ARTICLE{compas2021, author = {{Team COMPAS: Riley}, Jeff and {Agrawal}, Poojan and {Barrett}, Jim W. and {Boyett}, Kristan N.~K. and {Broekgaarden}, Floor S. and {Chattopadhyay}, Debatri and {Gaebel}, Sebastian M. and {Gittins}, Fabian and {Hirai}, Ryosuke and {Howitt}, George and {Justham}, Stephen and {Khandelwal}, Lokesh and {Kummer}, Floris and {Lau}, Mike Y.~M. and {Mandel}, Ilya and {de Mink}, Selma E. and {Neijssel}, Coenraad and {Riley}, Tim and {van Son}, Lieke and {Stevenson}, Simon and {Vigna-G{'o}mez}, Alejandro and {Vinciguerra}, Serena and {Wagg}, Tom and {Willcox}, Reinhold}, title = "{Rapid Stellar and Binary Population Synthesis with COMPAS}", journal = {\apjs}, keywords = {1622, 154, 1108, 162}, year = 2022, month = feb, volume = {258}, number = {2}, eid = {34}, pages = {34}, doi = {10.3847/1538-4365/ac416c}, adsurl = {https://ui.adsabs.harvard.edu/abs/2022ApJS..258...34R}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} }

@ARTICLE{compas2025, author = {{Team COMPAS: Mandel}, Ilya and {Riley}, Jeff and {Boesky}, Adam and {Brcek}, Adam and {Hirai}, Ryosuke and {Kapil}, Veome and {Lau}, Mike Y.~M. and {Merritt}, JD and {Rodr{'\i}guez-Segovia}, Nicol{'a}s and {Romero-Shaw}, Isobel and {Song}, Yuzhe and {Stevenson}, Simon and {Vajpeyi}, Avi and {van Son}, L.~A.~C. and {Vigna-G{'o}mez}, Alejandro and {Willcox}, Reinhold}, title = "{Rapid Stellar and Binary Population Synthesis with COMPAS: Methods Paper II}", journal = {\apjs}, keywords = {Binary stars, Stellar populations, Stellar evolution, Stellar evolutionary models, Stellar remnants, 154, 1622, 1599, 2046, 1627, Solar and Stellar Astrophysics, High Energy Astrophysical Phenomena, Instrumentation and Methods for Astrophysics}, year = 2025, month = sep, volume = {280}, number = {1}, eid = {43}, pages = {43}, doi = {10.3847/1538-4365/adf8d0}, archivePrefix = {arXiv}, eprint = {2506.02316}, primaryClass = {astro-ph.SR}, adsurl = {https://ui.adsabs.harvard.edu/abs/2025ApJS..280...43T}, adsnote = {Provided by the SAO/NASA Astrophysics Data System} }

##Note that the preferred acknowledgement relies on \noopsort and cites the paper as TEAM COMPAS; Riley et al.; to make it work, you'll have to include the following line at the start of your bibtex file: ##@PREAMBLE{ {\providecommand{\noopsort}[1]{}} }

##and change the author line in the bib entry to:

##author = {{\noopsort{Team COMPAS}}{Team COMPAS: Riley, J.} and {Agrawal}, Poojan and {Barrett}, Jim W. and {Boyett}, Kristan N.~K. and {Broekgaarden}, Floor S. and {Chattopadhyay}, Debatri and {Gaebel}, Sebastian M. and {Gittins}, Fabian and {Hirai}, Ryosuke and {Howitt}, George and {Justham}, Stephen and {Khandelwal}, Lokesh and {Kummer}, Floris and {Lau}, Mike Y.~M. and {Mandel}, Ilya and {de Mink}, Selma E. and {Neijssel}, Coenraad and {Riley}, Tim and {van Son}, Lieke and {Stevenson}, Simon and {Vigna-Gomez}, Alejandro and {Vinciguerra}, Serena and {Wagg}, Tom and {Willcox}, Reinhold}

In addition, we suggest to kindly include the two following papers:

1. Stevenson S., Vigna-Gómez A., Mandel I., Barrett J. W., Neijssel C. J., Perkins D., de Mink S. E., 2017, Nature Communications, 8, 14906
2. Vigna-Gómez A., Neijssel C. J., Stevenson S., Barrett J. W., Belczynski K., Justham S., de Mink S., Müller B., Podsiadlowski Ph., Renzo M., Szécsi D., Mandel I., 2018, MNRAS, 481, 4009

We also greatly appreciate an acknowledgement of the form:

Simulations in this paper made use of the COMPAS rapid binary population synthesis code (version X.X.X), which is freely available at http://github.com/TeamCOMPAS/COMPAS.

Furthermore,

• If you use COMPAS's importance sampling algorithm STROOPWAFEL, please cite

  Broekgaarden F. S., Justham S., de Mink S. E., Gair J., Mandel I., Stevenson S., Barrett J. W., Vigna-Gómez A., Neijssel C. J., 2019, MNRAS, 490, 5228

• If using the COMPAS model of gravitational wave selection effects, please cite

  Barrett J. W., Gaebel S. M., Neijssel C. J., Vigna-Gómez A., Stevenson S., Berry C. P. L., Farr W. M., Mandel I., 2018, MNRAS, 477, 4685

• If using COMPAS's integration over cosmic star formation history, please cite

  Neijssel C. J., Vigna-Gómez A., Stevenson S., Barrett J. W., Gaebel S. M., Broekgaarden F. S., de Mink S. E., Szécsi D., Vinciguerra S., Mandel I., 2019, MNRAS, 490, 3740

• If using the COMPAS model of (pulsational) pair instability supernova, please cite

  Stevenson S., Sampson M., Powell J., Vigna-Gómez A., Neijssel C. J., Szécsi D., Mandel I., 2019, ApJ, 882, 121

• If evolving pulsar spins and magnetic fields with COMPAS, please cite

  Chattopadhyay D., Stevenson S., Hurley J. R., Rossi L. J., Flynn C., 2020, MNRAS

License

MIT

Highlighted papers that have made use of COMPAS are listed at https://compas.science/science.html ; see https://ui.adsabs.harvard.edu/public-libraries/gzRk1qpbRUy4cP2GydR36Q for a full ADS library