Tidal dwarf galaxies in cosmological simulations

Understand

The formation and evolution of gravitationally bound, star forming substructures in tidal tails of interacting galaxies, called tidal dwarf galaxies (TDG), has been studied, until now, only in idealised simulations of individual pairs of interacting galaxies for pre-determined orbits, mass ratios, and gas fractions.

• Here, we present the first identification of TDG candidates in fully cosmological simulations, specifically the high-resolution simulations of the EAGLE suite.
• The finite resolution of the simulation limits their ability to predict the exact formation rate and survival timescale of TDGs, but we show that gravitationally bound baryonic structures in tidal arms already form in current state-of-the-art cosmological simulations.
• In this case, the orbital parameter, disc orientations as well as stellar and gas masses and the specific angular momentum of the TDG forming galaxies are a direct consequence of cosmic structure formation.