Resolution-independent modelling of environmental effects in semi-analytic models of galaxy formation that include ram-pressure stripping of both hot and cold gas

Abstract

The quenching of star formation in satellite galaxies is observed over a wide range of dark matter halo masses and galaxy environments. In the recent Guo et al (2011) and Fu et al (2013) semi-analytic + N-body models, the gaseous environment of the satellite galaxy is governed by the properties of the dark matter subhalo in which it resides. This quantity depends of the resolution of the N-body simulation, leading to a divergent fraction of quenched satellites in high-and low-resolution simulations. Here, we incorporate an analytic model to trace the subhaloes below the resolution limit. We demonstrate that we then obtain better converged results between the Millennium I and II simulations, especially for the satellites in the massive haloes (logM halo = [14, 15]). We also include a new physical model for the ram-pressure stripping of cold gas in satellite galaxies. However, we find very clear discrepancies with observed trends in quenched satellite galaxy fractions as a function of stellar mass at fixed halo mass. At fixed halo mass, the quenched fraction of satellites does not depend on stellar mass in the models, but increases strongly with mass in the data. In addition to the over-prediction of low-mass passive satellites, the models also predict too few quenched central galaxies with low stellar masses, so the problems in reproducing quenched fractions are not purely of environmental origin. Further improvements to the treatment of the gas-physical processes regulating the star formation histories of galaxies are clearly necessary to resolve these problems.

Physical drivers of galaxies’ cold-gas content: exploring environmental and evolutionary effects with Dark Sage

“…5a. Matching the observed quiescent fraction of galaxies as a function of stellar mass has proven challenging for semi-analytic models, especially for satellites (see, e.g., Font et al 2008;Guo et al 2011Guo et al , 2013Guo et al , 2016Croton et al 2016;Luo et al 2016;Henriques et al 2017). For the centrals, Dark Sage exhibits the common feature of overproducing low-mass quenched galaxies and underproducing high-mass quenched galaxies.…”

The JCMT Nearby Galaxies Legacy Survey – XI. Environmental variations in the atomic and molecular gas radial profiles of nearby spiral galaxies

“…It is likely that the NGLS is preferentially selecting galaxies that are recently infalling into the Virgo Cluster or have not been strongly affected by the cluster environment. In addition, due to the H I -flux criteria and with most of the galaxies in the resolved sample detected in the CO J = 3 − 2 maps, we are selecting relatively high stellar mass galaxies that are less likely to be fully stripped according to semi-analytical models (Luo et al 2016). Despite these caveats, the trends observed in the H I radial profile suggest that the environment can still play a big factor in changing the spatial distribution of the ISM inside these galaxies.…”

Survival of Massive Star-forming Galaxies in Cluster Cores Drives Gas-phase Metallicity Gradients: The Effects of Ram Pressure Stripping

“…Our disk truncation model Studying disk truncation in cluster satellites in its full complexity is very challenging because the simulation of full physics of multi-phase interstellar medium (ISM) and its hydrodynamical interaction with the ICM requires sophisticated modeling and can only be achieved using expensive, high-resolution numerical simulations (Roediger & Hensler 2005;Steinhauser et al 2016;Luo et al 2016). Hydrodynamical simulations use RPS of cold gas to obtain the star formation rate suppression and color transformation in simulated galaxy clusters (Abadi et al 1999;Balogh et al 2000;Roediger & Hensler 2005;Roediger & Brüggen 2007;Heß & Springel 2012;Steinhauser et al 2016).…”