---
res:
  bibo_abstract:
  - The mass assembly and chemical enrichment of the first galaxies provide key insights
    into their star formation histories and the earliest stellar populations at cosmic
    dawn. Here we compile and utilise new, high-quality spectroscopic JWST/NIRSpec
    Prism observations from the JWST archive. In particular, we extend the wavelength
    coverage beyond the standard pipeline cut-off (5.3 μm) up to 5.5 μm, which enables
    for the first time a detailed examination of the rest-frame optical emission-line
    properties for galaxies at z ≈ 10. Crucially, the improved calibration allows
    us to detect Hβ and the [O III] λλ4959, 5007 doublet and resolve the auroral [O III]
    λ4363 line for the 11 galaxies in our sample (z = 9.3 − 10.0) to obtain direct
    Te-based metallicity measurements. We find that the interstellar medium (ISM)
    of all galaxies shows high ionisation fields and electron temperatures, with derived
    metallicities in the range 12 + log(O/H) = 7.1 − 8.3 (3–50% solar), consistent
    with previous strong-line diagnostics based on JWST data at high redshifts. We
    derive an empirical relation for MUV and 12 + log(O/H) at z ≈ 10, useful for future
    higher-redshift studies, and show that the sample galaxies are ‘typical’ star-forming
    galaxies though with relatively high specific star formation rates (median sSFR
    = SFRHβ/M★ = 38 Gyr−1) and with evidence of bursty star formation on 10 Myr versus
    100 Myr timescales (log10(SFR10/SFR100)≈0.7). Combining the rest-frame optical
    line analysis and detailed UV to optical spectro-photometric modelling, we determine
    the mass-metallicity relation (MZR) and the fundamental metallicity relation (FMR)
    of the sample, pushing the previous redshift frontier of these measurements to
    z = 10. These results, together with literature measurements, point to a gradually
    decreasing MZR at higher redshifts, with a break in the FMR at z ≈ 3, decreasing
    to metallicities ≈3× lower at z = 10 than observed in galaxies during the majority
    of cosmic time at z = 0 − 3, likely caused by massive pristine gas inflows diluting
    the observed metal abundances during early galaxy assembly at cosmic dawn.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Clara L.
      foaf_name: Pollock, Clara L.
      foaf_surname: Pollock
  - foaf_Person:
      foaf_givenName: Rashmi
      foaf_name: Gottumukkala, Rashmi
      foaf_surname: Gottumukkala
  - foaf_Person:
      foaf_givenName: Kasper E.
      foaf_name: Heintz, Kasper E.
      foaf_surname: Heintz
  - foaf_Person:
      foaf_givenName: Gabriel B.
      foaf_name: Brammer, Gabriel B.
      foaf_surname: Brammer
  - foaf_Person:
      foaf_givenName: Guido
      foaf_name: Roberts-Borsani, Guido
      foaf_surname: Roberts-Borsani
  - foaf_Person:
      foaf_givenName: Pascal A.
      foaf_name: Oesch, Pascal A.
      foaf_surname: Oesch
  - foaf_Person:
      foaf_givenName: Joris
      foaf_name: Witstok, Joris
      foaf_surname: Witstok
  - foaf_Person:
      foaf_givenName: Karla Z.
      foaf_name: Arellano-Córdova, Karla Z.
      foaf_surname: Arellano-Córdova
  - foaf_Person:
      foaf_givenName: Fergus
      foaf_name: Cullen, Fergus
      foaf_surname: Cullen
  - foaf_Person:
      foaf_givenName: Dirk
      foaf_name: Scholte, Dirk
      foaf_surname: Scholte
  - foaf_Person:
      foaf_givenName: Chamilla
      foaf_name: Terp, Chamilla
      foaf_surname: Terp
  - foaf_Person:
      foaf_givenName: Lucie
      foaf_name: Rowland, Lucie
      foaf_surname: Rowland
  - foaf_Person:
      foaf_givenName: Albert
      foaf_name: Sneppen, Albert
      foaf_surname: Sneppen
  - foaf_Person:
      foaf_givenName: Kei
      foaf_name: Ito, Kei
      foaf_surname: Ito
  - foaf_Person:
      foaf_givenName: Francesco
      foaf_name: Valentino, Francesco
      foaf_surname: Valentino
  - foaf_Person:
      foaf_givenName: Jorryt J
      foaf_name: Matthee, Jorryt J
      foaf_surname: Matthee
      foaf_workInfoHomepage: http://www.librecat.org/personId=7439a258-f3c0-11ec-9501-9df22fe06720
    orcid: 0000-0003-2871-127X
  - foaf_Person:
      foaf_givenName: Darach
      foaf_name: Watson, Darach
      foaf_surname: Watson
  - foaf_Person:
      foaf_givenName: Sune
      foaf_name: Toft, Sune
      foaf_surname: Toft
  bibo_doi: 10.1051/0004-6361/202556032
  bibo_volume: 708
  dct_date: 2026^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0004-6361
  - http://id.crossref.org/issn/1432-0746
  dct_language: eng
  dct_publisher: EDP Sciences@
  dct_title: Novel z ∼ 10 auroral line measurements extend the gradual offset of the
    fundamental metallicity relation deep into the first gigayear of cosmic time@
...