TY - JOUR
T1 - The NIRVANDELS survey
T2 - the stellar and gas-phase mass-metallicity relations of star-forming galaxies at z = 3.5
AU - Stanton, T. M.
AU - Cullen, F.
AU - McLure, R. J.
AU - Shapley, A. E.
AU - Arellano-Córdova, K. Z.
AU - Begley, R.
AU - Amorín, R.
AU - Barrufet, L.
AU - Calabrò, A.
AU - Carnall, A. C.
AU - Cirasuolo, M.
AU - Dunlop, J. S.
AU - Donnan, C. T.
AU - Hamadouche, M. L.
AU - Liu, F. Y.
AU - McLeod, D. J.
AU - Pentericci, L.
AU - Pozzetti, L.
AU - Sanders, R. L.
AU - Scholte, D.
AU - Topping, M. W.
N1 - Publisher Copyright:
© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2024/8/1
Y1 - 2024/8/1
N2 - We present determinations of the gas-phase and stellar metallicities of a sample of 65 star-forming galaxies at z 3.5 using rest-frame far-ultraviolet (FUV) spectroscopy from the VANDELS survey in combination with follow-up rest-frame optical spectroscopy from VLT/KMOS and Keck/MOSFIRE. We infer gas-phase oxygen abundances (Zg; tracing O/H) via strong optical nebular lines and stellar iron abundances (Z*; tracing Fe/H) from full spectral fitting to the FUV continuum. Our sample spans the stellar mass range 8.5 < log(M*/M) < 10.5 and shows clear evidence for both a stellar and gas-phase mass-metallicity relation (MZR). We find that our O and Fe abundance estimates both exhibit a similar mass-dependence, such that Fe/H ∝ M*0.30±0.11 and O/H ∝ M*0.32±0.09. At fixed M* we find that, relative to their solar values, O abundances are systematically larger than Fe abundances (i.e. α-enhancement). We estimate an average enhancement of (O/Fe) = 2.65 ± 0.16 × (O/Fe) which appears to be independent of M*. We employ analytic chemical evolution models to place a constraint on the strength of galactic-level outflows via the mass-outflow factor (η). We show that outflow efficiencies that scale as η ∝ M*−0.32 can simultaneously explain the functional form of of the stellar and gas-phase MZR, as well as the degree of α-enhancement at fixed Fe/H. Our results add further evidence to support a picture in which α-enhanced abundance ratios are ubiquitous in high-redshift star-forming galaxies, as expected for young systems whose interstellar medium is primarily enriched by core-collapse supernovae.
AB - We present determinations of the gas-phase and stellar metallicities of a sample of 65 star-forming galaxies at z 3.5 using rest-frame far-ultraviolet (FUV) spectroscopy from the VANDELS survey in combination with follow-up rest-frame optical spectroscopy from VLT/KMOS and Keck/MOSFIRE. We infer gas-phase oxygen abundances (Zg; tracing O/H) via strong optical nebular lines and stellar iron abundances (Z*; tracing Fe/H) from full spectral fitting to the FUV continuum. Our sample spans the stellar mass range 8.5 < log(M*/M) < 10.5 and shows clear evidence for both a stellar and gas-phase mass-metallicity relation (MZR). We find that our O and Fe abundance estimates both exhibit a similar mass-dependence, such that Fe/H ∝ M*0.30±0.11 and O/H ∝ M*0.32±0.09. At fixed M* we find that, relative to their solar values, O abundances are systematically larger than Fe abundances (i.e. α-enhancement). We estimate an average enhancement of (O/Fe) = 2.65 ± 0.16 × (O/Fe) which appears to be independent of M*. We employ analytic chemical evolution models to place a constraint on the strength of galactic-level outflows via the mass-outflow factor (η). We show that outflow efficiencies that scale as η ∝ M*−0.32 can simultaneously explain the functional form of of the stellar and gas-phase MZR, as well as the degree of α-enhancement at fixed Fe/H. Our results add further evidence to support a picture in which α-enhanced abundance ratios are ubiquitous in high-redshift star-forming galaxies, as expected for young systems whose interstellar medium is primarily enriched by core-collapse supernovae.
KW - galaxies: abundances
KW - galaxies: evolution
KW - galaxies: high redshift
UR - http://www.scopus.com/inward/record.url?scp=85199440935&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85199440935&partnerID=8YFLogxK
U2 - 10.1093/mnras/stae1705
DO - 10.1093/mnras/stae1705
M3 - Article
AN - SCOPUS:85199440935
SN - 0035-8711
VL - 532
SP - 3102
EP - 3119
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -