{"acknowledgement":"We thank the referee for thoughtful and constructive comments that have improved the quality of this manuscript. Based on observations collected at the European Southern Observatory under ESO programme 1101.A-0127. This work made use of v2.2.1 of the Binary Population and Spectral Synthesis (BPASS) models as described in Eldridge et al. (2017) and Stanway & Eldridge (2018). A.F. acknowledges the support from grant PRIN MIUR2017-20173ML3WW_001. T.N. acknowledges support from Australian Research Council Laureate Fellowship FL180100060.","article_processing_charge":"No","month":"03","date_created":"2022-07-05T15:25:35Z","citation":{"ieee":"J. J. Matthee <i>et al.</i>, “Deciphering stellar metallicities in the early universe: Case study of a young galaxy at z = 4.77 in the MUSE eXtremely Deep Field,” <i>Astronomy &#38; Astrophysics</i>, vol. 660. EDP Sciences, 2022.","short":"J.J. Matthee, A. Feltre, M. Maseda, T. Nanayakkara, L. Boogaard, R. Bacon, A. Verhamme, F. Leclercq, H. Kusakabe, T. Urrutia, L. Wisotzki, Astronomy &#38; Astrophysics 660 (2022).","mla":"Matthee, Jorryt J., et al. “Deciphering Stellar Metallicities in the Early Universe: Case Study of a Young Galaxy at z = 4.77 in the MUSE EXtremely Deep Field.” <i>Astronomy &#38; Astrophysics</i>, vol. 660, A10, EDP Sciences, 2022, doi:<a href=\"https://doi.org/10.1051/0004-6361/202142187\">10.1051/0004-6361/202142187</a>.","ama":"Matthee JJ, Feltre A, Maseda M, et al. Deciphering stellar metallicities in the early universe: Case study of a young galaxy at z = 4.77 in the MUSE eXtremely Deep Field. <i>Astronomy &#38; Astrophysics</i>. 2022;660. doi:<a href=\"https://doi.org/10.1051/0004-6361/202142187\">10.1051/0004-6361/202142187</a>","apa":"Matthee, J. J., Feltre, A., Maseda, M., Nanayakkara, T., Boogaard, L., Bacon, R., … Wisotzki, L. (2022). Deciphering stellar metallicities in the early universe: Case study of a young galaxy at z = 4.77 in the MUSE eXtremely Deep Field. <i>Astronomy &#38; Astrophysics</i>. EDP Sciences. <a href=\"https://doi.org/10.1051/0004-6361/202142187\">https://doi.org/10.1051/0004-6361/202142187</a>","chicago":"Matthee, Jorryt J, Anna Feltre, Michael Maseda, Themiya Nanayakkara, Leindert Boogaard, Roland Bacon, Anne Verhamme, et al. “Deciphering Stellar Metallicities in the Early Universe: Case Study of a Young Galaxy at z = 4.77 in the MUSE EXtremely Deep Field.” <i>Astronomy &#38; Astrophysics</i>. EDP Sciences, 2022. <a href=\"https://doi.org/10.1051/0004-6361/202142187\">https://doi.org/10.1051/0004-6361/202142187</a>.","ista":"Matthee JJ, Feltre A, Maseda M, Nanayakkara T, Boogaard L, Bacon R, Verhamme A, Leclercq F, Kusakabe H, Urrutia T, Wisotzki L. 2022. Deciphering stellar metallicities in the early universe: Case study of a young galaxy at z = 4.77 in the MUSE eXtremely Deep Field. Astronomy &#38; Astrophysics. 660, A10."},"external_id":{"arxiv":["2111.14855"]},"status":"public","oa":1,"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","extern":"1","type":"journal_article","date_updated":"2022-07-19T09:33:46Z","volume":660,"publication_identifier":{"eissn":["1432-0746"],"issn":["0004-6361"]},"_id":"11490","doi":"10.1051/0004-6361/202142187","author":[{"id":"7439a258-f3c0-11ec-9501-9df22fe06720","last_name":"Matthee","orcid":"0000-0003-2871-127X","first_name":"Jorryt J","full_name":"Matthee, Jorryt J"},{"first_name":"Anna","full_name":"Feltre, Anna","last_name":"Feltre"},{"first_name":"Michael","full_name":"Maseda, Michael","last_name":"Maseda"},{"full_name":"Nanayakkara, Themiya","first_name":"Themiya","last_name":"Nanayakkara"},{"first_name":"Leindert","full_name":"Boogaard, Leindert","last_name":"Boogaard"},{"last_name":"Bacon","full_name":"Bacon, Roland","first_name":"Roland"},{"last_name":"Verhamme","full_name":"Verhamme, Anne","first_name":"Anne"},{"last_name":"Leclercq","first_name":"Floriane","full_name":"Leclercq, Floriane"},{"last_name":"Kusakabe","first_name":"Haruka","full_name":"Kusakabe, Haruka"},{"first_name":"Tanya","full_name":"Urrutia, Tanya","last_name":"Urrutia"},{"last_name":"Wisotzki","full_name":"Wisotzki, Lutz","first_name":"Lutz"}],"article_number":"A10","abstract":[{"text":"Directly characterising the first generations of stars in distant galaxies is a key quest of observational cosmology. We present a case study of ID53 at z = 4.77, the UV-brightest (but L⋆) star-forming galaxy at z > 3 in the MUSE eXtremely Deep Field with a mass of ≈109 M⊙. In addition to very strong Lyman-α (Lyα) emission, we clearly detect the (stellar) continuum and an N V P Cygni feature, interstellar absorption, fine-structure emission and nebular C IV emission lines in the 140 h spectrum. Continuum emission from two spatially resolved components in Hubble Space Telescope data are blended in the MUSE data, but we show that the nebular C IV emission originates from a subcomponent of the galaxy. The UV spectrum can be fit with recent BPASS stellar population models combined with single-burst or continuous star formation histories (SFHs), a standard initial mass function, and an attenuation law. Models with a young age and low metallicity (log10(age/yr) = 6.5–7.6 and [Z/H] = −2.15 to −1.15) are preferred, but the details depend on the assumed SFH. The intrinsic Hα luminosity of the best-fit models is an order of magnitude higher than the Hα luminosity inferred from Spitzer/IRAC data, which either suggests a high escape fraction of ionising photons, a high relative attenuation of nebular to stellar dust, or a complex SFH. The metallicity appears lower than the metallicity in more massive galaxies at z = 3 − 5, consistent with the scenario according to which younger galaxies have lower metallicities. This chemical immaturity likely facilitates Lyα escape, explaining why the Lyα equivalent width is anti-correlated with stellar metallicity. Finally, we stress that uncertainties in SFHs impose a challenge for future inferences of the stellar metallicity of young galaxies. This highlights the need for joint (spatially resolved) analyses of stellar spectra and photo-ionisation models.","lang":"eng"}],"publication_status":"published","publication":"Astronomy & Astrophysics","keyword":["Space and Planetary Science","Astronomy and Astrophysics","galaxies: high-redshift / techniques: spectroscopic / galaxies: stellar content / galaxies: formation"],"day":"30","article_type":"original","publisher":"EDP Sciences","year":"2022","date_published":"2022-03-30T00:00:00Z","language":[{"iso":"eng"}],"intvolume":"       660","scopus_import":"1","quality_controlled":"1","title":"Deciphering stellar metallicities in the early universe: Case study of a young galaxy at z = 4.77 in the MUSE eXtremely Deep Field","main_file_link":[{"url":"https://arxiv.org/abs/2111.14855","open_access":"1"}],"oa_version":"Published Version"}