Ilya Mandel, Jeff Riley, Adam Boesky, Adam Brcek, Ryosuke Hirai, Veome Kapil, Mike Y. M. Lau, JD Merritt, Nicolás Rodríguez-Segovia, Isobel Romero-Shaw, Yuzhe Song, Simon Stevenson, Avi Vajpeyi, L. A. C. van Son, Alejandro Vigna-Gómez, Reinhold Willcox

The COMPAS public rapid binary population synthesis code has undergone a number of key improvements since the original COMPAS methods paper (Team COMPAS: Riley et al., 2022) 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 v03.20.02.