Year: 2025
Type: article
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.
Authors: Yifan Mai, Scott M Croom, Emily Wisnioski, Andrew J Battisti, J Trevor Mendel, Marcie Mun, Caroline Foster, Katherine E Harborne, Claudia D P Lagos, Iris Breda, Tianmu Gao, Kathryn Grasha, Tamal Mukherjee, Adriano Poci, Rhea-Silvia Remus, Piyush Sharda, Sarah M Sweet, Sabine Thater, Lucas M Valenzuela, Glenn van de Ven, Tayyaba Zafar, Bodo Ziegler
Institutions: The University of Sydney, ASTRO-3D, ARC Centre of Excellence for All-sky Astrophysics, Australian Astronomical Optics, Macquarie University, Australian National University, The University of Western Australia, International Centre for Radio Astronomy Research, UNSW Sydney, Durham University, University of Vienna, University of Oxford, Ludwig-Maximilians-Universität München, Leiden University, Leiden Observatory, The University of Queensland
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
Funders: Gruber Foundation, American Academy of Ophthalmology, Australian Government, Royal Society, European Commission, Universiteit Leiden, Universität Wien, Studienstiftung des Deutschen Volkes, International Astronomical Union, Science and Technology Facilities Council, Australian Research Council, Elitenetzwerk Bayern, Division of Arctic Sciences
Awards: Understanding diversity: chemical and kinematic tracers of galaxy evolution, G2976739200, G434337789, ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions, G4907986279, G5462808729, G6073949366, G6416677464, Time takes its toll: understanding why galaxies slow down as they get older, G7915199406, G8669201118
OpenAlex ID: W4417199245