Rapid Stellar and Binary Population Synthesis with COMPAS: Methods Paper II

The COMPAS (https://compas.science) public rapid binary population synthesis code has undergone a number of key improvements since the original COMPAS methods paper was published. These include more sophisticated and robust treatments of binary interactions: mass transfer physics; common-envelope events; tides and gravitational-wave radiation reaction; and updated prescriptions for stellar evolution, winds, and supernovae. The code structure and outputs have also been updated, with a focus on improving resolution without sacrificing computational speed. This paper describes the substantive changes in the code between the previous methods paper and COMPAS v03.22.01.