Giovanni Mirouh (Surrey)
Detailed equilibrium and dynamical tides: impact on circularization and synchronization in open clusters
Binary stars evolve into chemically-peculiar objects and are a major driver of the Galactic enrichment of heavy elements. During their evolution they undergo interactions, including tides, that circularize their orbits and synchronize stellar spins, impacting both individual systems and stellar populations.
This work introduces an accurate implementation of equilibrium and dynamical tides in the stellar population code binary_c, relying on Zahn’s theory and MESA model grids. I will first introduce the stellar population code itself, and the overhaul that we call MINT.
We assess the impact of tides and initial orbital-parameter distributions on circularization and synchronization processes in open clusters. Studying the eccentricity-period diagram, we find that the initial distributions dominate the agreement with observations so that tidal prescriptions hardly make a difference: this makes constraining tidal-efficiency parameters using the e-logP distribution alone difficult, or even impossible. Instead, we find that the synchronization process carries a more striking signature of the tides, thus providing a measure of tidal efficiency that is verifiable with combined measurements of orbital parameters and stellar spins.