Radialization of satellite orbits in galaxy mergers

Understand

We consider the orbital evolution of satellites in galaxy mergers, focusing on the evolution of eccentricity.

• Using a large suite of N-body simulations, we study the phenomenon of satellite orbital radialization -- a profound increase in the eccentricity of its orbit as it decays under dynamical friction.
• While radialization is detected in a variety of different setups, it is most efficient in the cases of high satellite mass, not very steep host density profiles, and high initial eccentricity.
• To understand the origin of this phenomenon, we run additional simulations with various physical factors selectively turned off: satellite mass loss, reflex motion and distortion of the host, etc.