---
res:
  bibo_abstract:
  - "An accurate characterisation of the physical properties of galaxies at cosmic
    dawn is key to understanding\r\nthe origin of the high abundance of UV-bright
    galaxies at z≳10. We exploit deep (9.1-hour exposure time)\r\nNIRSpec PRISM observations
    of GHZ2 to constrain the sources of ionising radiation and the properties of the\r\ninterstellar
    medium (ISM) in this bright, compact, and highly ionising galaxy at z=12.3. We
    measure with\r\nhigh significance the prominent N IV, C IV, He II, O III, C III,
    O II, and Ne III emission features previously\r\ndetected in shallower observations,
    and confirm the detection of the N III] λ1750 multiplet, yielding tight\r\nconstraints
    on the N/O ratio, which is found to be ≃2 times the solar value. We also detect
    the Mg II λ2800,\r\n[Fe IV] λ2833 and Si II λ1812 doublets, the H8+HeI λλ3889
    blend, and the Si IV+O IV] λλ1400 absorption\r\ncomplex. The O III λ3133 fluorescence
    line is only detected in the first observing epoch, implying variability\r\non
    a rest-frame time span of 19 days, strongly suggesting the presence of an active
    nucleus. Combining the\r\nNIRSpec dataset with available optical and far-infrared
    constraints from MIRI and ALMA, we show that the\r\nemission spectrum of GHZ2
    cannot be reproduced by single-density spectro-photometric models, even under\r\nextreme
    assumptions on the ionisation parameter and electron density. Multi-zone photoionisation
    modelling\r\nperformed with the HOMERUN code demonstrates that star formation
    must be occurring in a strongly stratified\r\nISM, where both low-/intermediate-density
    gas and high-density regions (log(ne/cm−3\r\n) ≳ 4) coexist. The\r\nGHZ2 emission
    landscape is consistent with either a composite star-formation plus AGN scenario,
    or with\r\nstar formation occurring in a combination of radiation- and matter-bounded
    regions. Purely radiation-bounded\r\nstellar models fail to reproduce the observed
    He II emission, making an additional hard ionising component\r\nunavoidable.@eng"
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: M.
      foaf_name: Castellano, M.
      foaf_surname: Castellano
  - foaf_Person:
      foaf_givenName: L.
      foaf_name: Napolitano, L.
      foaf_surname: Napolitano
  - foaf_Person:
      foaf_givenName: B.
      foaf_name: Moreschini, B.
      foaf_surname: Moreschini
  - foaf_Person:
      foaf_givenName: A.
      foaf_name: Calabrò, A.
      foaf_surname: Calabrò
  - foaf_Person:
      foaf_givenName: L.
      foaf_name: Christensen, L.
      foaf_surname: Christensen
  - foaf_Person:
      foaf_givenName: M.
      foaf_name: Llerena, M.
      foaf_surname: Llerena
  - foaf_Person:
      foaf_givenName: T. J.L.C.
      foaf_name: Bakx, T. J.L.C.
      foaf_surname: Bakx
  - foaf_Person:
      foaf_givenName: F.
      foaf_name: Belfiore, F.
      foaf_surname: Belfiore
  - foaf_Person:
      foaf_givenName: D.
      foaf_name: Bevacqua, D.
      foaf_surname: Bevacqua
  - foaf_Person:
      foaf_givenName: M.
      foaf_name: Dickinson, M.
      foaf_surname: Dickinson
  - foaf_Person:
      foaf_givenName: A.
      foaf_name: Fontana, A.
      foaf_surname: Fontana
  - foaf_Person:
      foaf_givenName: G.
      foaf_name: Gandolfi, G.
      foaf_surname: Gandolfi
  - foaf_Person:
      foaf_givenName: T.
      foaf_name: Gasparetto, T.
      foaf_surname: Gasparetto
  - foaf_Person:
      foaf_givenName: A.
      foaf_name: Marconi, A.
      foaf_surname: Marconi
  - foaf_Person:
      foaf_givenName: Sara
      foaf_name: Mascia, Sara
      foaf_surname: Mascia
      foaf_workInfoHomepage: http://www.librecat.org/personId=edaf889c-c7cd-11ef-ab1b-bb28c431bd29
  - foaf_Person:
      foaf_givenName: E.
      foaf_name: Merlin, E.
      foaf_surname: Merlin
  - foaf_Person:
      foaf_givenName: T.
      foaf_name: Morishita, T.
      foaf_surname: Morishita
  - foaf_Person:
      foaf_givenName: T.
      foaf_name: Nanayakkara, T.
      foaf_surname: Nanayakkara
  - foaf_Person:
      foaf_givenName: D.
      foaf_name: Paris, D.
      foaf_surname: Paris
  - foaf_Person:
      foaf_givenName: L.
      foaf_name: Pentericci, L.
      foaf_surname: Pentericci
  - foaf_Person:
      foaf_givenName: B.
      foaf_name: Pérez-Díaz, B.
      foaf_surname: Pérez-Díaz
  - foaf_Person:
      foaf_givenName: G.
      foaf_name: Roberts-Borsani, G.
      foaf_surname: Roberts-Borsani
  - foaf_Person:
      foaf_givenName: S.
      foaf_name: Rojas-Ruiz, S.
      foaf_surname: Rojas-Ruiz
  - foaf_Person:
      foaf_givenName: P.
      foaf_name: Santini, P.
      foaf_surname: Santini
  - foaf_Person:
      foaf_givenName: T.
      foaf_name: Treu, T.
      foaf_surname: Treu
  - foaf_Person:
      foaf_givenName: E.
      foaf_name: Vanzella, E.
      foaf_surname: Vanzella
  - foaf_Person:
      foaf_givenName: B.
      foaf_name: Vulcani, B.
      foaf_surname: Vulcani
  - foaf_Person:
      foaf_givenName: X.
      foaf_name: Wang, X.
      foaf_surname: Wang
  - foaf_Person:
      foaf_givenName: I.
      foaf_name: Yoon, I.
      foaf_surname: Yoon
  - foaf_Person:
      foaf_givenName: J.
      foaf_name: Zavala, J.
      foaf_surname: Zavala
  bibo_doi: 10.33232/001c.160281
  bibo_volume: 9
  dct_date: 2026^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/2565-6120
  dct_language: eng
  dct_publisher: Maynooth Academic Publishing@
  dct_title: Investigating ionising sources and the complex interstellar medium of
    GHZ2 at z=12.3@
...