# Refueled and shielded - The early evolution of Tidal Dwarf Galaxies

## TL;DR

This study uses advanced simulations to show how the tidal arm environment significantly influences the evolution, gas content, and star formation in young tidal dwarf galaxies, highlighting the importance of realistic initial conditions.

## Contribution

First numerical simulations of young tidal dwarf galaxies embedded in tidal arms, demonstrating their impact on galaxy evolution and star formation compared to isolated models.

## Key findings

- Embedding in tidal arms doubles gas mass and gas fraction.
- Increases stellar mass by 50% and star formation rate by a factor of 3.
- Environmental effects like tidal field and ram pressure show no clear impact in the studied scenario.

## Abstract

We present, for the first time, numerical simulations of young tidal dwarf galaxies (TDGs), including a self-consistent treatment of the tidal arm in which they are embedded. Thereby, we do not rely on idealised initial conditions, as the initial data of the presented simulation emerge from a galaxy interaction simulation. By comparing models which are either embedded in or isolated form the tidal arm, we demonstrate its importance on the evolution of TDGs, as additional source of gas which can be accreted and is available for subsequent conversion into stars. During the initial collapse of the proto-TDG, with a duration of a few 100 Myr, the evolution of the embedded and isolated TDGs are indistinguishable. Significant differences appear after the collapse has halted and the further evolution is dominated by the possible accretion of material form the surroundings of the TDGs. The inclusion of the tidal arm in the simulation of TDGs results in roughly a doubling of the gas mass ($M_\mathrm{gas}$) and gas fraction ($f_\mathrm{gas}$), an increase in stellar mass by a factor of 1.5 and a $\sim3$ times higher star formation rate (SFR) compared to the isolated case. Moreover, we perform a parametric study on the influence of different environmental effects, i.e. the tidal field and ram pressure. Due to the orbit of the chosen initial conditions, no clear impact of the environmental effects on the evolution of TDG candidates can be found.