The MAGPI Survey: forward modelled gas-phase metallicity gradients in galaxies at <i>z</i> ∼ 0.3

ABSTRACT We measure the seeing-deconvolved gas-phase metallicity gradients of 70 star-forming galaxies at $z\sim 0.3$ from the MAGPI survey and investigate their relationship with galaxy properties to understand the mechanisms that influence the distribution of metals and shape the evolution of the galaxies. We use a Bayesian modelling technique, blobby3d, which accounts for seeing effects (beam smearing) and can model the substructures of the flux distribution. The median metallicity gradient of our sample is $\nabla \mathrm{[O/H]}=-0.013^{+0.059}_{-0.033}$ dex kpc−1. Among the galaxies in our sample, 32.9 per cent have negative metallicity gradients (2$\sigma$ significance), 10.0 per cent have positive gradients and 57.1 per cent have flat gradients. The $\nabla \mathrm{[O/H]}$–$M_*$ relation of the MAGPI galaxies generally agrees with theoretical predictions, where a combination of stellar feedback, gas transport, and accretion shapes the metallicity profile, with the dominant processes varying with galaxy mass. We find a positive correlation between $\nabla \mathrm{[O/H]}$ and gas velocity dispersion ($r=0.36$), indicating that stronger gas turbulence is associated with flatter or inverted metallicity gradients, likely due to enhanced gas mixing. Additionally, smaller galaxies tend to have flatter or positive gradients, suggesting that metal dilution by gas accretion or removal via feedback-driven winds may outweigh metal enrichment in small galaxies.

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Journal
Monthly Notices of the Royal Astronomical Society
Published
2025-12-09
DOI
https://doi.org/10.1093/mnras/staf2182
Primary Topic
Galaxies: Formation, Evolution, Phenomena
Type
article
Field-Weighted Citation Impact
0.00

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article

The MAGPI Survey: forward modelled gas-phase metallicity gradients in galaxies at z ∼ 0.3

Yifan Mai, B. Ziegler, Caroline Foster, Lucas M. Valenzuela et al.
Monthly Notices of the Royal Astronomical Society
Galaxies: Formation, Evolution, Phenomena
article

The MAGPI Survey: forward modelled gas-phase metallicity gradients in galaxies at z ∼ 0.3

Yifan Mai, B. Ziegler, Caroline Foster, Lucas M. Valenzuela, Rhea–Silvia Remus, Tayyaba Zafar, Marcie Mun, Kathryn Grasha, Sabine Thater, K. E. Harborne, Glenn van de Ven, J. Trevor Mendel, Tianmu Gao, Claudia del P. Lagos, Iris Breda, S. M. Croom, Adriano Poci, Sarah M. Sweet, Piyush Sharda, Andrew Battisti, Emily Wisnioski, Tamal Mukherjee
article en

Abstract

ABSTRACT We measure the seeing-deconvolved gas-phase metallicity gradients of 70 star-forming galaxies at $z\sim 0.3$ from the MAGPI survey and investigate their relationship with galaxy properties to understand the mechanisms that influence the distribution of metals and shape the evolution of the galaxies. We use a Bayesian modelling technique, blobby3d, which accounts for seeing effects (beam smearing) and can model the substructures of the flux distribution. The median metallicity gradient of our sample is $\nabla \mathrm{[O/H]}=-0.013^{+0.059}_{-0.033}$ dex kpc−1. Among the galaxies in our sample, 32.9 per cent have negative metallicity gradients (2$\sigma$ significance), 10.0 per cent have positive gradients and 57.1 per cent have flat gradients. The $\nabla \mathrm{[O/H]}$–$M_*$ relation of the MAGPI galaxies generally agrees with theoretical predictions, where a combination of stellar feedback, gas transport, and accretion shapes the metallicity profile, with the dominant processes varying with galaxy mass. We find a positive correlation between $\nabla \mathrm{[O/H]}$ and gas velocity dispersion ($r=0.36$), indicating that stronger gas turbulence is associated with flatter or inverted metallicity gradients, likely due to enhanced gas mixing. Additionally, smaller galaxies tend to have flatter or positive gradients, suggesting that metal dilution by gas accretion or removal via feedback-driven winds may outweigh metal enrichment in small galaxies.

Monthly Notices of the Royal Astronomical SocietyVol. 545(3)
Australian National University (AU), Leiden University (NL), The University of Sydney (AU), University of Vienna (AT), The University of Queensland (AU), The University of Western Australia (AU), Durham University (GB), Australian Astronomical Observatory (AU), UNSW Sydney (AU), University of Oxford (GB), Australian Hearing (AU), ARC Centre of Excellence for All-sky Astrophysics (AU), International Centre for Radio Astronomy Research (AU), Ludwig-Maximilians-Universität München (DE), Macquarie University (AU)
Gruber Foundation, Australian Government, European Commission, Universiteit Leiden, Universität Wien, Studienstiftung des Deutschen Volkes, Science and Technology Facilities Council, Elitenetzwerk Bayern
Openalex Percentile: Top 73%
Galaxies: Formation, Evolution, Phenomena
DOIOpen Access PDFOpenAlex
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