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- Wilkins, Stephen M., et al.
(författare)
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First Light And Reionization Epoch Simulations (FLARES) VII : The star formation and metal enrichment histories of galaxies in the early Universe
- 2023
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 518:3, s. 3935-3948
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Tidskriftsartikel (refereegranskat)abstract
- The star formation and metal enrichment histories of galaxies - at any epoch - constitute one of the key properties of galaxies, and their measurement is a core aim of observational extragalactic astronomy. The lack of deep rest-frame optical coverage at high redshift has made robust constraints elusive, but this is now changing thanks to JWST. In preparation for the constraints provided by JWST, we explore the star formation and metal enrichment histories of galaxies at z = 5-13 using the First Light And Reionization Epoch Simulations (FLARES) suite. Built on the EAGLE model, the unique strategy of FLARES allows us to simulate galaxies with a wide range of stellar masses (and luminosities) and environments. While we predict significant redshift evolution of average ages and specific star formation rates, our core result is mostly a flat relationship of age and specific star formation rate with stellar mass. We also find that galaxies in this epoch predominantly have strongly rising star formation histories, albeit with the normalization dropping with redshift and stellar mass. In terms of chemical enrichment, we predict a strong stellar mass-metallicity relation present at z = 10 and beyond alongside significant a-enhancement. Finally, we find no large-scale environmental dependence of the relationship between age, specific star formation rate, or metallicity with stellar mass.
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| 2. |
- Wilkins, Stephen M., et al.
(författare)
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First Light and Reionization Epoch Simulations (flares) - XIV. The Balmer/4000 Ã… breaks of distant galaxies
- 2023
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 527:3, s. 7965-7973
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Tidskriftsartikel (refereegranskat)abstract
- With the successful launch and commissioning of JWST we are now able to routinely spectroscopically probe the rest-frame optical emission of galaxies at z > 6 for the first time. Among the most useful spectral diagnostics used in the optical is the Balmer/4000 & Aring; break; this is, in principle, a diagnostic of the mean ages of composite stellar populations. However, the Balmer break is also sensitive to the shape of the star formation history, the stellar (and gas) metallicity, the presence of nebular continuum emission, and dust attenuation. In this work, we explore the origin of the Balmer/4000 & Aring; break using the SYNTHESIZER synthetic observations package. We then make predictions of the Balmer/4000 & Aring; break using the First Light and Reionization Epoch Simulations at 5 < z < 10. We find that the average break strength weakly correlates with stellar mass and rest-frame far-ultraviolet luminosity, but that this is predominantly driven by dust attenuation. We also find that break strength provides a weak diagnostic of the age but performs better as a means to constrain star formation and stellar mass, alongside the ultraviolet and optical luminosity, respectively.
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