Modern tidal interaction models for rapid binary population synthesis: I. Methods

TL;DR

This paper introduces an efficient, updated tidal dissipation model integrated into binary population synthesis, capturing stellar structure effects and showing significantly stronger tidal effects compared to traditional models.

Contribution

The authors develop a simplified yet physically motivated tidal dissipation prescription for rapid binary evolution modeling, implemented in the COMPAS code.

Findings

Tidal dissipation efficiencies can be 1-2 orders of magnitude stronger for low-mass stars.

Dynamical tides can be 1-7 orders of magnitude stronger due to stellar structure dependence.

Models agree with detailed simulations within an order of magnitude.

Abstract

In this work, we present an updated prescription of contemporary tidal dissipation theory adapted for rapid binary population synthesis. Our simplified expressions encode the dependence of tidal dissipation on stellar structure, stratification, and tidal forcing frequency, while remaining computationally efficient. We implement these prescriptions in the rapid population synthesis code COMPAS, and demonstrate the self-consistent coupling of tides with stellar evolution and binary properties such as orbital periods, spins, and eccentricities for several representative binary systems. When compared with commonly used tidal prescriptions, our equilibrium tidal dissipation efficiencies can be stronger by 1-2 orders of magnitude for low mass main sequence and giant type stars, and dynamical tides can be stronger by 1-7 orders of magnitude due to the explicit dependence on internal stellar structure and the presence of inertial wave dissipation. Despite our simplistic approach, our models agree with detailed stellar simulations to within an order of magnitude across tidal dissipation mechanisms.