The NIRVANDELS Survey: a robust detection of α-enhancement in star-forming galaxies at z ≃ 3.4
Year: 2021
Type: article
Abstract: ABSTRACT We present results from the NIRVANDELS survey on the gas-phase metallicity (Zg, tracing O/H) and stellar metallicity (Z⋆, tracing Fe/H) of 33 star-forming galaxies at redshifts 2.95 < z < 3.80. Based on a combined analysis of deep optical and near-IR spectra, tracing the rest-frame far-ultraviolet (FUV; 1200–2000 Å) and rest-frame optical (3400–5500 Å), respectively, we present the first simultaneous determination of the stellar and gas-phase mass–metallicity relationships (MZRs) at z ≃ 3.4. In both cases, we find that metallicity increases with increasing stellar mass (M⋆) and that the power-law slope at M⋆ ≲ 1010M⊙ of both MZRs scales as $Z \propto M_{\star }^{0.3}$. Comparing the stellar and gas-phase MZRs, we present direct evidence for super-solar O/Fe ratios (i.e. α-enhancement) at z > 3, finding (O/Fe) = 2.54 ± 0.38 × (O/Fe)⊙, with no clear dependence on M⋆.
Authors: F Cullen, A E Shapley, R J McLure, J S Dunlop, R L Sanders, M W Topping, N A Reddy, R Amorín, R Begley, M Bolzonella, A Calabrò, A C Carnall, M Castellano, A Cimatti, M Cirasuolo, G Cresci, A Fontana, F Fontanot, B Garilli, L Guaita, M Hamadouche, N P Hathi, F Mannucci, D J McLeod, L Pentericci, A Saxena, M Talia, G Zamorani
Institutions: Royal Observatory, University of Edinburgh, University of California, Los Angeles, University of California, Davis, University of California, Riverside, University of La Serena, Osservatorio astronomico di Bologna, National Institute for Astrophysics, Astronomical Observatory of Rome, Arcetri Astrophysical Observatory, University of Bologna, European Southern Observatory, Trieste Astronomical Observatory, Universidad Andrés Bello, Space Telescope Science Institute, University College London
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,247
Awards: G3156532051, G6216976133, G7021558607
OpenAlex ID: W3134819838