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A Composite Rest-Frame UV Spectrum of Galaxies at $5.7 < z < 6.9$: Ionization, Outflows, and Implications for Intergalactic Metal Enrichment — arXiv:2610.33154

Source: arXiv (en)
Original: https://arxiv.org/abs/2610.33154
License (as archived): CC0-1.0
Archived: 2026-11-03T11:50:57.931Z
SHA-256 of the archived text: 5f281360d39c40662f6da00cae2416fd8d3bdb621b09b277072f2d94b93b8375
Stable URL of this page: https://metraipolis.com/documento/dc_a50f00a28207

How to cite

A Composite Rest-Frame UV Spectrum of Galaxies at $5.7 < z < 6.9$: Ionization, Outflows, and Implications for Intergalactic Metal Enrichment — arXiv:2610.33154 — arXiv (en), https://arxiv.org/abs/2610.33154 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_a50f00a28207 (Metraipolis archive dc_a50f00a28207, sha256 5f281360d39c40662f6da00cae2416fd8d3bdb621b09b277072f2d94b93b8375)

BibTeX

@misc{dca50f00a28207,
  title = {A Composite Rest-Frame UV Spectrum of Galaxies at $5.7 < z < 6.9$: Ionization, Outflows, and Implications for Intergalactic Metal Enrichment — arXiv:2610.33154},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2610.33154},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_a50f00a28207; sha256 5f281360d39c40662f6da00cae2416fd8d3bdb621b09b277072f2d94b93b8375},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2610.33154. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

We present a stacked JWST/NIRSpec spectrum of 104 galaxies at $\lambda_{\rm rest}=1200\unicode{x2013}2000\;\mathrm{\mathring{A}}$ to study nebular emission and absorption from the interstellar medium (ISM) and stellar winds. The sample is drawn from known [O III] emitters with mean redshift $z=6.50$, absolute UV magnitude $M_\mathrm{UV}=-20.7$, and stellar mass $M_{\star}=10^{8.93}\;\mathrm{M_\odot}$. The stacked continuum closely resembles lower-redshift Lyman Break Galaxy composites, with a few notable differences. Ly$\;\alpha$ has comparable strength and is redshifted relative to the [O III] systemic frame, consistent with production in gaseous outflows. High-ionization emission lines including O III], C III], and He II are slightly stronger than in lower-redshift stacks but exhibit narrow widths, disfavoring ionization from a broad-line AGN. Emission-line ratios slightly favor ionization by a hard stellar continuum, though a contribution from a narrow-line nuclear source cannot be strictly excluded. Numerous strong absorption lines at both high and low ionization are blueshifted by $\sim200\;\mathrm{km\,s^{-1}}$, again indicating outflows driven by stellar winds or entrained metal-enriched ISM. A simple model suggests that at $z\sim6.5$ most star-forming galaxies are too young for winds at these velocities to propagate beyond $\sim3\unicode{x2013}9$ proper kpc, implying that the observed [O III] emitter population alone cannot explain the frequency of heavy-element absorbers seen in quasar spectra. In this picture, early enrichment of the intergalactic medium likely arises from undetected low-mass galaxies ($M_\star\sim10^5\unicode{x2013}10^6\;\mathrm{M_\odot}$) clustered around the more massive systems detected in JWST/NIRCam WFSS surveys.

Tema degli esploratori: fisica e astronomia (elenco arXiv astro-ph.CO, nuovi lavori del giorno).
Categorie arXiv: Astrophysics of Galaxies (astro-ph.GA) ; Cosmology and Nongalactic Astrophysics (astro-ph.CO).
Pagina del lavoro: https://arxiv.org/abs/2610.33154 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-11-03T11:12:22.672Z dalla pagina https://arxiv.org/list/astro-ph.CO/new (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).