A Self-Consistent, Time-Dependent Treatment of Dynamical Friction: New Insights regarding Core Stalling and Dynamical Buoyancy

Understand

Dynamical friction is typically regarded a secular process, in which the subject ('perturber') evolves very slowly (secular approximation), and has been introduced to the host over a long time (adiabatic approximation).

• These assumptions imply that dynamical friction arises from the LBK torque with non-zero contribution only from pure resonance orbits.
• However, dynamical friction is only of astrophysical interest if its timescale is shorter than the age of the Universe.
• In this paper we therefore relax the adiabatic and secular approximations.