TAPIR Seminar

In person: 370 Cahill. To Join via Zoom: 868 5298 8404

ABSTRACT: Triple systems are frequent among stellar systems, and their evolution may lead to a wide variety of non-trivial and sometimes exotic outcomes. These systems can experience nonstable mass transfer episodes and a common envelope evolution (CEE), and they can change their orbits due to the dynamical effects of the 3-body interaction with the gas.

CEE, which plays a major role in the evolution of compact binary systems, can similarly play a key role in the evolution of triples. Here I use hydrodynamical simulations coupled with few-body dynamics to provide the first detailed models of triple common envelope (TCE) evolution. We will discuss two scenarios of the TCE, according to the distant third component of the hierarchical system, which can either be the donor star (circumstellar case), or one of the accretors (circumbinary case). I will show that these events can lead to the formation of many possible outcomes, among them are various types of stellar mergers, unique compact binary systems, and potentially induce electromagnetic transients and gravitational-wave sources.

If time permits, I will present a simplified model to predict the outcome of direct and indirect collision of two CO white dwarfs (WDs), that can result from a previous triple interaction. Using our high-resolution simulations with AREPO, we can construct detonation criteria that can provide the critical impact parameter for an explosion to occur, depending on the density profile of the colliding WDs, their composition, and their collision velocities. These criteria can be later used to perform population studies.