Formation and evolution of substructures in tidal tails: spherical dark matter haloes

Abstract

Recently a theory about the formation of over-densities of stars along tidal tails of globular clusters has been presented, this theory predicts the position and time of formation of such over-densities and was successfully tested with N-body simulations of globular clusters in a point mass galactic potential. In this work we present a comparison between this theory and our simulations using a dwarf galaxy orbiting two differently shaped dark matter halos to study the effects of a cored and a cuspy halo on the formation and evolution of tidal tails. We find no difference using a cuspy or a cored halo, however, we find an intriguing asymmetry between the leading and trailing arm of the tidal tails. The trailing arm grows faster than the leading arm. This asymmetry is seen in the distance to first over-density and its size as well. We establish a relation between the distance to the first over-density and the size of this over-density.

Asymmetrical tidal tails of open star clusters: stars crossing their cluster’s práh† challenge Newtonian gravitation

“…that modelling a satellite galaxy in Newtonian gravitation, Reinoso et al (2018) find the position of the first Küpper overdensity to be correlated with the orbital distance and the mass of the satellite. They also find the first Küpper epicyclic overdensity to be closer to the satellite in the leading tail than in the trailing tail (their fig.…”