I'm currently studying the orbit of some satellite subhalos around their respective hosts and I want to know the value of its ellipticity. Is there any field I can ask for using any of the IllustrisTNG modules or functions that retrieves it?
There is no information about orbits in any TNG data - you can get samples of an orbit (i.e. the past position of a galaxy) using the merger tree, then you could classify this evolution in terms of an ellipticity parameter, but you would need to make this calculation yourself.
Thank you for the help! I will go with the merger tree function then.