The MAGPI survey: evolution of radial trends in star formation activity across cosmic time
Abstract
Using adaptive optics with the Multi-Unit Spectroscopic Explorer on the Very Large Telescope, the Middle Ages Galaxy Properties with Integral Field Spectroscopy survey allows us to study the spatially resolved Universe at a crucial time of ~4 Gyr ago (z ~ 0.3) when simulations predict the greatest diversity in evolutionary pathways for galaxies. We investigate the radial trends in the star formation (SF) activity and luminosity-weighted stellar ages as a function of offset from the star-forming main sequence (SFMS) for a total of 294 galaxies. Using both Hα emission and the 4000 Å break (i.e. D4000) as star formation rate (SFR) tracers, we find overall flat radial profiles for galaxies lying on and above the SFMS, suggestive of physical processes that enhance/regulate SF throughout the entire galaxy disc. However, for galaxies lying below the SFMS, we find positive gradients in SF suggestive of inside-out quenching. Placing our results in context with results from other redshift regimes suggests an evolution in radial trends at z ~ 0.3 for SF galaxies above the SFMS, from uniformly enhanced SF at z ~ 1 and ~ 0.3 to centrally enhanced SF at z ~ 0 (when averaged over a wide range of mass). We also capture higher local SFRs for galaxies below the SFMS compared to that of z ~ 0, which can be explained by a larger population of quenched satellites in the local Universe and/or different treatments of limitations set by the D4000-sSFR relation.
- Publication:
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Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2024
- DOI:
- 10.1093/mnras/stae1132
- arXiv:
- arXiv:2404.16319
- Bibcode:
- 2024MNRAS.530.5072M
- Keywords:
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- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 19 pages, 15 figures, 4 tables, accepted for publication in MNRAS