The role of gas kinematics in setting metallicity gradients at high redshift

Abstract

In this work, we explore the diversity of ionised gas kinematics (rotational velocity $v_{\varphi }$ and velocity dispersion ${\sigma }_{\mathrm{g}}$) and gas-phase metallicity gradients at $0.1\le z\le 2.5$ using a compiled data set of 74 galaxies resolved with ground-based integral field spectroscopy. We find that galaxies with the highest and the lowest ${\sigma }_{\mathrm{g}}$ have preferentially flat metallicity gradients, whereas those with intermediate values of ${\sigma }_{\mathrm{g}}$ show a large scatter in the metallicity gradients. Additionally, steep negative gradients appear almost only in rotation-dominated galaxies ($v_{\varphi }/{\sigma }_{\mathrm{g}}>1$), whereas most dispersion-dominated galaxies show flat gradients. We use our recently developed analytic model of metallicity gradients to provide a physical explanation for the shape and scatter of these observed trends. In the case of high ${\sigma }_{\mathrm{g}}$, the inward radial advection of gas dominates over metal production and causes efficient metal mixing, thus giving rise to flat gradients. For low ${\sigma }_{\mathrm{g}}$, it is the cosmic accretion of metal-poor gas diluting the metallicity that gives rise to flat gradients. Finally, the reason for intermediate ${\sigma }_{\mathrm{g}}$ showing the steepest negative gradients is that both inward radial advection and cosmic accretion are weak as compared to metal production, which leads to the creation of steeper gradients. The larger scatter at intermediate ${\sigma }_{\mathrm{g}}$ may be due in part to preferential ejection of metals in galactic winds, which can decrease the strength of the production term. Our analysis shows how gas kinematics play a critical role in setting metallicity gradients in high-redshift galaxies.

15 pages, 10 figures. Accepted by MNRAS

References in corpus (38)

• Array Programming with NumPy
• The Host Galaxies and Classification of Active Galactic Nuclei
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• The MUSE second-generation VLT instrument
• The KMOS^3D Survey: design, first results, and the evolution of galaxy kinematics from 0.7<z<2.7
• Understanding Galaxy Evolution through Emission Lines
• The Evolution of the Star-forming Interstellar Medium across Cosmic Time
• Strongly baryon-dominated disk galaxies at the peak of galaxy formation ten billion years ago
• Star-Forming Galaxies at Cosmic Noon
• The KMOS^3D Survey: data release and final survey paper
• z~2: An Epoch of Disk Assembly
• Rotation Curves in z~1-2 Star-Forming Disks: Evidence for Cored Dark Matter Distributions
• LZIFU: an emission-line fitting toolkit for integral field spectroscopy data
• The KLEVER Survey: Spatially resolved metallicity maps and gradients in a sample of 1.2 < z < 2.5 lensed galaxies
• A relationship between specific star formation rate and metallicity gradient within z=1 galaxies from KMOS-HiZELS
• Gas-phase metallicity gradients of TNG50 star-forming galaxies
• The physics of gas phase metallicity gradients in galaxies
• CLEAR: The Gas-Phase Metallicity Gradients of Star-Forming Galaxies at 0.6 < z < 2.6
• The Grism Lens-Amplified Survey from Space (GLASS). II. Gas-phase metallicity and radial gradients in an interacting system at z~2
• Measuring the mixing scale of the ISM within nearby spiral galaxies
• Distinguishing Mergers and Disks in High Redshift Observations of Galaxy Kinematics
• Mixing and transport of metals by gravitational instability-driven turbulence in galactic discs
• From global to spatially resolved in low-redshift galaxies
• The KMOS${}^{3D}$ Survey: Investigating the Origin of the Elevated Electron Densities in Star-Forming Galaxies at $1\lesssim z\lesssim 3$
• The MAGPI Survey -- science goals, design, observing strategy, early results and theoretical framework
• On the origin of the mass-metallicity gradient relation in the local Universe
• Inferring gas-phase metallicity gradients of galaxies at the seeing limit: A forward modelling approach
• The evolution of the metallicity gradient and the star formation efficiency in disc galaxies
• Kinematic Evolution of Simulated Star-Forming Galaxies
• The Evolution of Gas-Phase Metallicity and Resolved Abundances in Star-forming Galaxies at $z\approx 0.6-1.8$
• Flat Rotation Curves of $z\sim 1$ Star-Forming Galaxies and Evidence of Disk-Scale Length Evolution
• Detection of metallicity correlations in 100 nearby galaxies
• A re-assessment of strong line metallicity conversions in the machine learning era
• The redshift evolution of the baryonic Tully-Fisher relation in Simba
• Quasi-equilibrium models of high-redshift disc galaxy evolution
• SPICA and the Chemical Evolution of Galaxies: The Rise of Metals and Dust
• Phase A Science Case for MAVIS -- The Multi-conjugate Adaptive-optics Visible Imager-Spectrograph for the VLT Adaptive Optics Facility
• Simulating gas kinematic studies of high-redshift galaxies with the HARMONI Integral Field Spectrograph

Cited by in corpus (11)

• The physics of gas phase metallicity gradients in galaxies
• Distant Echoes of the Milky Way's Last Major Merger
• Gas Accretion Can Drive Turbulence in Galaxies
• The interplay between feedback, accretion, transport and winds in setting gas-phase metal distribution in galaxies
• The resolved chemical abundance properties within the interstellar medium of star-forming galaxies at $\text{z}\approx 1.5$
• Insights on Metal Enrichment and Environmental Effect at $z\approx 5-7$ with JWST ASPIRE/EIGER and Chemical Evolution Model
• MASCOT: Molecular gas depletion times and metallicity gradients -- evidence for feedback in quenching active galaxies
• A path towards constraining the evolution of the interstellar medium and outflows in the Milky Way using APOGEE
• The ALPINE-CRISTAL-JWST Survey: Gas-phase abundance gradients of main sequence star-forming galaxies and their kinematics at $4<z<6$
• When did the initial mass function become bottom-heavy?
• KURVS: chemical properties from multiple strong line calibrations for star-forming galaxies at $z\sim 1.5$