Rhapsody-G simulations – II. Baryonic growth and metal enrichment in massive galaxy clusters

Abstract

We study the evolution of the stellar component and the metallicity of both the intracluster medium and of stars in massive (M vir « 6ˆ10 14 M d {h) simulated galaxy clusters from the Rhapsody-G suite in detail and compare them to observational results. The simulations were performed with the AMR code RAMSES and include the effect of AGN feedback at the sub-grid level. AGN feedback is required to produce realistic galaxy and cluster properties and plays a role in mixing material in the central regions and regulating star formation in the central galaxy. In both our low and high resolution runs with fiducial stellar yields, we find that stellar and ICM metallicities are a factor of two lower than in observations. We find that cool core clusters exhibit steeper metallicity gradients than non-cool core clusters, in qualitative agreement with observations. We verify that the ICM metallicities measured in the simulation can be explained by a simple "regulator" model in which the metallicity is set by a balance of stellar yield and gas accretion. It is plausible that a combination of higher resolution and higher metal yield in AMR simulation would allow the metallicity of simulated clusters to match observed values; however this hypothesis needs to be tested with future simulations. Comparison to recent literature highlights that results concerning the metallicity of clusters and cluster galaxies might depend sensitively on the scheme chosen to solve the hydrodynamics.

Enrichment of the Hot Intracluster Medium: Numerical Simulations

“…More recently, advanced cosmological hydrodynamical simulations performed with various codes, both SPH and grid-based, have combined chemical models with several other physical processes, including feedback from stellar and active galactic nuclei (AGN) sources, with the purpose of obtaining more realistic simulations of galaxy clusters that can be compared against the increasingly detailed observational databases available (Sijacki and Springel 2006;Puchwein et al 2008;Fabjan et al 2010;Dubois et al 2011;Planelles et al 2014;Martizzi et al 2016;Biffi et al 2017;Barnes et al 2017;.…”

“…Since the late 90s, several groups started to couple chemical evolution models with hydrodynamical simulations of galaxies (Raiteri et al 1996;Mosconi et al 2001), and of galaxy clusters (Lia et al 2002;Kawata and Gibson 2003;Valdarnini 2003;Tornatore et al 2004;Scannapieco et al 2005;Davé et al 2008;Wiersma et al 2009b). In the past 15 years, advancements in the modelling of the chemical properties have also been accompanied by substantial improvements in the description of the various physical processes driving the evolution of the baryonic component, such has energy feedback from stellar and AGN sources Scannapieco et al 2005;Sijacki and Springel 2006;Fabjan et al 2010;Dubois et al 2011;Planelles et al 2014;Martizzi et al 2016; Barnes et al 2017). Despite some limitations still persist (e.g.…”

“…on the details of the baryonic cycle in cluster cores and of the feedback scheme), cluster simulations have reached an unprecedented level of detail. Recent simulation campaigns carried on by different groups have in fact succeeded in reproducing more realistic cluster properties, for instance recovering the observed thermal and chemical diversity of cool-core and non-cool-core clusters (Rasia et al 2015;Hahn et al 2015;Martizzi et al 2016;Biffi et al 2017;Barnes et al 2018;. Although not discussed in this paper, theoretical investigations of the chemical enrichment of the inter-galactic gas in clusters and groups have also been pursued via semi-analytical techniques, coupling DM-only or non-radiative simulations with semi-analytical models of galaxy formation and evolution that account, with various level of detail, for the chemical enrichment processes from SN explosions and AGB stars in galaxies.…”

Dark Energy Survey Year 1 Results: Detection of Intracluster Light at Redshift ∼ 0.25

“…Due to its low surface brightness and diffuseness, studying the ICL presents significant challenges. Simulation ICL studies generally require high resolution (Contini et al 2014) as well as proper baryonic physics such as active galactic nucleus (AGN) feedback (Martizzi et al 2016;Pillepich et al 2018) to trace the dispersion of stellar particles. Observational studies using the Hubble Space Telescope (HST) tend to be pointed observations and benefit from the high resolution and low sky background level of the images but are limited to small cluster samples.…”

Stellar-mass Measurements in A133 with Magellan/IMACS

“…Furthermore, the distribution of stellar material and hot gas within clusters should bear the imprint of key processes shaping galaxy formation. Indeed, observed stellar mass fractions and stellar mass function of cluster galaxies have become valuable benchmarks for testing models of feedback in cosmological simulations of cluster formation (e.g., Martizzi et al 2014Martizzi et al , 2016Bahé et al 2017;McCarthy et al 2017;Cui et al 2018;Pillepich et al 2018;Henden et al 2018). The radial profile of stellar density of the Brightest Cluster Galaxy (BCG), as well as the radial distribution of stellar mass in galaxies are potentially equally powerful constraints on the models (e.g., Martizzi et al 2014;Bellstedt et al 2018).Despite recent progress (Gonzalez et al 2013;Budzynski et al 2012Budzynski et al , 2014Kravtsov et al 2018;Huang et al 2018), the number of clusters with available accurate measurements of the gas mass, stellar mass in galaxies down to dwarf scales, and stellar material in the outer envelope of the central galaxy remains small.…”