---
res:
  bibo_abstract:
  - "We present the discovery of extreme nitrogen enrichment by Wolf Rayet nitrogen
    (WN) stars in the metal-poor (∼10%Z⊙), lensed, compact (Reff ∼ 20 pc) galaxy RXCJ2248
    at z = 6.1, revealed by unprecedentedly deep\r\nJWST/NIRSpec medium-resolution
    spectroscopy from the GLIMPSE-D Survey. The exquisite signal-to-noise\r\nratio
    reveals multiple high-ionization nebular lines and broad Balmer and [O III] components
    (FWHM\r\n∼700–3000 km s\r\n−1\r\n). We detect broadened He II λ1640 and λ4687
    (FWHM ∼ 530 km s\r\n−1\r\n) and strong N III λ4642\r\nemission consistent with
    a population of WN stars, making RXCJ2248 the most distant galaxy with confirmed\r\nWolf
    Rayet (WR) features to date. We measure the multiphase nebular density across
    five ions, the direct-method\r\nmetallicity (\r\n12 + log(O/H) = 7.753 ± 0.025\r\n),
    and a nonuniform elemental enrichment pattern of extreme N/O\r\nenhancement (\r\nlog(N/O)
    = 0.391 ± 0.037\r\nfrom N+, N+2\r\n, and N+3\r\n) but suppressed C/O relative
    to empirical\r\nC/N trends. We show that this abundance pattern can be explained
    by enrichment from a dual-burst with a low\r\nWR carbon/WN ratio, as expected
    at low metallicities. Crucially, these signatures can only arise during a brief,\r\nrare
    evolutionary window shortly after a burst (∼3–6 Myr), when WN stars dominate chemical
    feedback but\r\nbefore dilution by later yields (e.g., supernovae). The observed
    frequency of strong N emitters at high−z implies a\r\n∼50 Myr burst duty cycle,
    suggesting that N/O outliers may represent a brief but ubiquitous phase in the\r\nevolution
    of highly star-forming early galaxies. The WN detection in RXCJ2248, therefore,
    provides the first\r\ndirect evidence of WR-driven nitrogen enrichment in the
    first billion years of the Universe and a novel timing\r\nargument for the bursty
    star formation cycles that shaped galaxies at cosmic dawn.@eng"
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Danielle A.
      foaf_name: Berg, Danielle A.
      foaf_surname: Berg
  - foaf_Person:
      foaf_givenName: Rohan P.
      foaf_name: Naidu, Rohan P.
      foaf_surname: Naidu
  - foaf_Person:
      foaf_givenName: John
      foaf_name: Chisholm, John
      foaf_surname: Chisholm
  - foaf_Person:
      foaf_givenName: Hakim
      foaf_name: Atek, Hakim
      foaf_surname: Atek
  - foaf_Person:
      foaf_givenName: Seiji
      foaf_name: Fujimoto, Seiji
      foaf_surname: Fujimoto
  - foaf_Person:
      foaf_givenName: Vasily
      foaf_name: Kokorev, Vasily
      foaf_surname: Kokorev
  - foaf_Person:
      foaf_givenName: Lukas J.
      foaf_name: Furtak, Lukas J.
      foaf_surname: Furtak
  - foaf_Person:
      foaf_givenName: Chiaki
      foaf_name: Kobayashi, Chiaki
      foaf_surname: Kobayashi
  - foaf_Person:
      foaf_givenName: Daniel
      foaf_name: Schaerer, Daniel
      foaf_surname: Schaerer
  - foaf_Person:
      foaf_givenName: Angela
      foaf_name: Adamo, Angela
      foaf_surname: Adamo
  - foaf_Person:
      foaf_givenName: Qinyue
      foaf_name: Fei, Qinyue
      foaf_surname: Fei
  - foaf_Person:
      foaf_givenName: Damien
      foaf_name: Korber, Damien
      foaf_surname: Korber
  - 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: Rui
      foaf_name: Marques-Chaves, Rui
      foaf_surname: Marques-Chaves
  - foaf_Person:
      foaf_givenName: Zorayda
      foaf_name: Martinez, Zorayda
      foaf_surname: Martinez
  - foaf_Person:
      foaf_givenName: Kristen B.W.
      foaf_name: Mcquinn, Kristen B.W.
      foaf_surname: Mcquinn
  - foaf_Person:
      foaf_givenName: Julian B.
      foaf_name: Muñoz, Julian B.
      foaf_surname: Muñoz
  - foaf_Person:
      foaf_givenName: Pascal A.
      foaf_name: Oesch, Pascal A.
      foaf_surname: Oesch
  - foaf_Person:
      foaf_givenName: Alberto
      foaf_name: Saldana-Lopez, Alberto
      foaf_surname: Saldana-Lopez
  - foaf_Person:
      foaf_givenName: Daniel P.
      foaf_name: Stark, Daniel P.
      foaf_surname: Stark
  - foaf_Person:
      foaf_givenName: Mabel G.
      foaf_name: Stephenson, Mabel G.
      foaf_surname: Stephenson
  - foaf_Person:
      foaf_givenName: Tiger Yu Yang
      foaf_name: Hsiao, Tiger Yu Yang
      foaf_surname: Hsiao
  bibo_doi: 10.3847/1538-4357/ae5e4c
  bibo_issue: '2'
  bibo_volume: 1003
  dct_date: 2026^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0004-637X
  - http://id.crossref.org/issn/1538-4357
  dct_language: eng
  dct_publisher: IOP Publishing@
  dct_title: 'A fleeting GLIMPSE of N/O enrichment at cosmic dawn: Evidence for Wolf
    Rayet N stars in a z = 6.1 galaxy@'
...