From dark-matter subhaloes to satellite galaxies — building a new semi-analytic emulator of cosmological zoom-in simulations.
Abstract:
We present a work in progress, on the development of a new semi-analytic model for satellite galaxies, “SatGen”. The model is devised to generate large statistical samples of satellite-galaxy populations for targeted host systems of desired mass, formation history, and redshift. It consists of halo merger trees and analytic prescriptions for describing tidal stripping, tidal heating, dynamical friction, and ram-pressure stripping. SatGen emulates cosmological zoom-in hydro-simulations. Notably, satellites can reside in cored or cuspy dark-matter subhaloes, and the central system can be a combination of disc, bulge, and DM halo, with each component described by a profile with simple analytics suitable for fast orbital integration. SatGen outperforms simulations regarding the ability of generating large samples of satellite-galaxy populations, which enables the study of halo-to-halo variance of satellite statistics, and the ability of resolving dwarf galaxies of extreme structures. We address key improvements with respect to earlier models, discuss the model recipes that incorporate important wisdom of galaxy-halo connection and tidal evolution extracted from high-resolution cosmological or idealized simulations, and overview possible applications of the model.