Speaker
Description
The mechanics of binary evolution remain largely invisible other than the luminosities that reach us. However, these luminosities are the end result of a chain of interdependent feedback processes spanning the entire binary system to accrete material from a still-evolving donor star. With recent developments a clear picture of this mass transfer is now possible. Only by tackling system dynamics across evolutionary timescales can we truly understand the the evolution of close binary stars.
In this talk, I will describe in detail my novel approach to track mass transfer hydrodynamics in high-resolution 3D across system evolution. This model captures the donor envelope, wind, tidal stream, accretion disk, and X-ray feedback interacting in tandem. These regimes are collectively evolved through the new method of Time-Incremented Multiscale Evolution (TIME). This enables variable time resolution by cyclical feedback between 3D hydrodynamics and 1D binary evolution codes.
This model is capable of translating a 1D profile accounting for tidal deformations into a 3D stellar envelope while retaining hydrostatic equilibrium everywhere well away from the inner Lagrange point. This enables smooth feedback between dynamical and evolutionary codes without introducing artifacts due to model relaxation.
It is now possible to model long evolutionary timescales while fitting 3D sub-orbital timescale dynamics, in a new milestone for stellar evolution.
I will discuss my results in the context of several previously under-constrained quantities in binary interactions. I conclude that the wind Roche lobe overflow mode can persist at higher filling factors than previously thought ($f>1$). On the opposite end, I identify binary mass transfer more than 10% overflowing ($f>1.1$) to be necessarily brief ($<100$ years).
Finally, I will plot the course for future developments in binary models towards high-resolution 3D models of nuclear-timescale mass transfer in the next few years.
| Talk category | NOVA Network 2 |
|---|---|
| Second preference | NOVA Network 3 |
