Making Counter-Orbiting Tidal Debris: The Origin of the Milky Way Disc of Satellites

Understand

Using stellar-dynamical calculations it is shown for the first time that counter-orbiting material emerges naturally in tidal interactions of disc galaxies.

• Model particles on both pro- and retrograde orbits can be formed as tidal debris in single encounters with disc galaxies of 1-to-1 and 4-to-1 mass ratios.
• A total of 74 model calculations are performed for a range of different initial parameters.
• Interactions include fly-by and merger cases.