Dynamics in gas is different

by Ms. Mor Rozner

Technion

at Astrophysics and Cosmology Seminar

Wed, 19 Jun 2024, 11:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

Gas-rich environments are abundant in the Universe and include AGN disks, star-forming regions, protoplanetary disks and regions of late star formation in globular clusters. While the dynamics of binaries in gas-free environments have been studied extensively, gas-rich environments are fertile ground for phenomena that are still largely unexplored, and in this talk, we will discuss some of the unique phenomena of dynamics in gas.
Binaries tend statistically to get softer as they encounter other stars, according to Heggie's law. However, in gas-rich environments, this law should be modified as gas-hardening could lead to a significant energy dissipation that could dominate over stellar softening. Here we explore the effect of gas hardening on the softening rate of binaries and its implications.
We will also discuss gas-assisted binary formation. In gaseous media, interactions between two initially unbound objects could result in gas-assisted binary formation, induced by a loss of kinetic energy to the ambient gas medium. Here, we derive analytically the criteria for gas-assisted binary capture through gas dynamical friction dissipation.
In some environments, these captures could occur more than once per object, leading to multicaptures. We will discuss that and further implications.

Created on 13-06-2024 by Zitrin, Adi (zitrin)
Updaded on 13-06-2024 by Zitrin, Adi (zitrin)