The Stellar Chemical Abundances of Simulated Massive Galaxies at $z=2$

Abstract

We analyze the stellar abundances of massive galaxies ($\log M_{\ast }/M_{\odot }>10.5$) at $z=2$ in the IllustrisTNG simulation with the goal of guiding the interpretation of current and future observations, particularly from the James Webb Space Telescope. We find that the effective size, $R_e$, of galaxies strongly affects the abundance measurements: both [Mg/H] and [Fe/H] are anti-correlated with $R_e$, while the relative abundance [Mg/Fe] slightly increases with $R_e$. The $\alpha$ enhancement as tracked by [Mg/Fe] traces the formation timescale of a galaxy weakly, and mostly depends on $R_e$. Aperture effects are important: measuring the stellar abundances within 1~kpc instead of within $R_e$ can make a large difference. These results are all due to a nearly universal, steeply declining stellar abundance profile that does not scale with galaxy size -- small galaxies appear metal-rich because their stars live in the inner part of the profile where abundances are high. The slope of this profile is mostly set by the gas-phase abundance profile and not substantially modified by stellar age gradients. The gas-phase abundance profile, in turn, is determined by the strong radial dependence of the gas fraction and star formation efficiency. We develop a simple model to describe the chemical enrichment, in which each radial bin of a galaxy is treated as an independent closed-box system. This model reproduces the gas-phase abundance profile of simulated galaxies, but not the detailed distribution of their stellar abundances, for which gas and/or metal transport are likely needed.

arXiv comment16 pages, 12+2 figures, accepted for publication in MNRAS

References in corpus (55)

• The chemical composition of the Sun
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Simulating Galaxy Formation with the IllustrisTNG Model
• First results from the IllustrisTNG simulations: matter and galaxy clustering
• First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies
• First results from the IllustrisTNG simulations: the galaxy color bimodality
• Properties of galaxies reproduced by a hydrodynamic simulation
• First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium
• Simulating galaxy formation with black hole driven thermal and kinetic feedback
• The ages and metallicities of galaxies in the local universe
• First results from the IllustrisTNG simulations: radio haloes and magnetic fields
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• Stellar population models of Lick indices with variable element abundance ratios
• The Stellar Population Histories of Early-Type Galaxies. II. Controlling Parameters of the Stellar Populations
• De Re Metallica: The cosmic chemical evolution of galaxies
• Strangulation as the primary mechanism for shutting down star formation in galaxies
• The Origin of the Galaxy Mass-Metallicity Relation and Implications for Galactic Outflows
• The Atlas3D Project - XXX. Star formation histories and stellar population scaling relations of early-type galaxies
• The Origin and Evolution of the Galaxy Mass-Metallicity Relation
• Environment and self-regulation in galaxy formation
• The CALIFA survey across the Hubble sequence: Spatially resolved stellar population properties in galaxies
• The Metallicity of Galaxy Disks: Infall versus Outflow
• The evolution of the mass-metallicity relation in IllustrisTNG
• The relationship between black hole mass and galaxy properties: Examining the black hole feedback model in IllustrisTNG
• The VLT LEGA-C Spectroscopic Survey: The Physics of Galaxies at a Lookback Time of 7 Gyr
• The Stellar Initial Mass Function in Early-Type Galaxies from Absorption Line Spectroscopy. III. Radial Gradients
• A Critical Assessment of Stellar Mass Measurement Methods
• Chemical Cartography with APOGEE: Multi-element abundance ratios
• Origin of chemically distinct discs in the Auriga cosmological simulations
• A massive, quiescent, population II galaxy at a redshift of 2.1
• Gas accretion and galactic fountain flows in the Auriga cosmological simulations: angular momentum and metal re-distribution
• Gas-phase metallicity gradients of TNG50 star-forming galaxies
• Why do high-redshift galaxies show diverse gas-phase metallicity gradients?
• From 'bathtub' galaxy evolution models to metallicity gradients
• Tracing Outflowing Metals in Simulations of Dwarf and Spiral Galaxies
• The SAMI Galaxy Survey: gravitational potential and surface density drive stellar populations -- I. early-type galaxies
• Stellar Metallicities and Elemental Abundance Ratios of z~1.4 Massive Quiescent Galaxies
• Resolved galaxy scaling relations in the EAGLE simulation: star formation, metallicity and stellar mass on kpc scales
• The origin of the enhanced metallicity of satellite galaxies
• Toward a Better Understanding of Cosmic Chronometers: Stellar Population Properties of Passive Galaxies at Intermediate Redshift
• Elemental Abundances and Ages of $z\sim 0.7$ Quiescent Galaxies on the Mass-Size Plane: Implication for Chemical Enrichment and Star-Formation Quenching
• The mass-metallicity relation at z~1-2 and its dependence on star formation rate
• Resolved Multi-element Stellar Chemical Abundances in the Brightest Quiescent Galaxy at z $\sim$ 2
• The stellar metallicities of massive quiescent galaxies at 1.0 < z < 1.3 from KMOS+VANDELS
• Time Evolution of Galaxy Scaling Relations in Cosmological Simulations
• The evolution of galaxy metallicity scaling relations in cosmological hydrodynamical simulations
• Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate and α-enhancement
• Biases and systematics in the observational derivation of galaxy properties: comparing different techniques on synthetic observations of simulated galaxies
• Explaining the scatter in the galaxy mass-metallicity relation with gas flows
• Stellar population properties of individual massive early-type galaxies at 1.4 < z < 2
• The Impact of Outflows driven by Active Galactic Nuclei on Metals in and around Galaxies
• Stellar mass as the "glocal" driver of galaxies' stellar population properties
• Physical properties of galaxies: toward a consistent comparison between hydrodynamical simulations and SDSS
• On the variation in stellar $\alpha$-enhancements of star-forming galaxies in the EAGLE simulation

Cited by in corpus (1)

• Growing in number, passive in nature: tracing the evolution of the most massive quiescent galaxies since z ~ 0.8 with BOSS and DESI