{
  "abstract": "We present James Web Space Telescope/NIRSpec dense-shutter spectroscopy (DSS). This novel observing strategy with the NIRSpec/multi-shutter assembly (MSA) deliberately permits a high number of controlled spectral overlaps to reach extreme multiplex while retaining the low background of slit spectroscopy. In a single configuration over the JADES Origins Field, we opened shutters on all faint ($m_\\mathrm{F444W}\\lt 30$ mag) $z_{\\rm phot}\\gt 3$ candidates, prioritizing emission-line science and rejecting only bright continuum sources. Using 33.6 and 35.8 ks on-source in G235M and G395M, we observed a single mask with $\\sim$850 sources, obtaining spectroscopic redshifts for $\\sim$540 galaxies over $2.5\\lesssim z \\lesssim 8.9$. The per-configuration target density in DSS mode is 4–5$\\times$ higher than standard no- and low-overlap MSA strategies (<200 sources), with no loss in redshift precision or accuracy. Line-flux sensitivities are 30 per cent lower at fixed exposure time, matching the expected increase in background noise, but the gain in survey speed is 5$\\times$ in our setup, more than justifying the penalty. The measured line sensitivity exceeds NIRCam slitless spectroscopy by at least ${\\sim} 5\\times$ (${\\sim} 25\\times$ in exposure time) at $\\lambda \\sim 4~\\mu {\\rm m}$, demonstrating that DSS is a compelling method to gain deep, wide-band spectra for large samples. Crucially, NIRSpec/MSA could deliver even higher target allocation densities than those used here. We derive H α-based star-formation rates, gas-phase metallicities (including a large sample suitable for strong-line calibrations), and identify rare mini-quenched galaxies and broad-line AGN. DSS is immediately applicable wherever deep imaging enables robust pre-selection and astrometry, providing an efficient method to obtain large samples of faint emission-line galaxies, a compelling middle ground between the completeness of slitless surveys and the sensitivity and bandwidth of NIRSpec/MSA.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2510.11626",
  "author_total": 43,
  "authors": [
    {
      "name": "Francesco D’eugenio"
    },
    {
      "name": "Erica Nelson"
    },
    {
      "name": "Daniel Eisenstein"
    },
    {
      "name": "Roberto Maiolino"
    },
    {
      "name": "Stefano Carniani"
    },
    {
      "name": "Jan Scholtz"
    },
    {
      "name": "Mirko Curti"
    },
    {
      "name": "Christopher Willmer"
    },
    {
      "name": "Andrew Bunker"
    },
    {
      "name": "Jakob Helton"
    },
    {
      "name": "Ignas Juodžbalis"
    },
    {
      "name": "Fengwu Sun"
    },
    {
      "name": "Sandro Tacchella"
    },
    {
      "name": "Santiago Arribas"
    },
    {
      "name": "Alex Cameron"
    },
    {
      "name": "Stéphane Charlot"
    },
    {
      "name": "Emma Curtis-Lake"
    },
    {
      "name": "Kevin Hainline"
    },
    {
      "name": "Benjamin Johnson"
    },
    {
      "name": "Brant Robertson"
    },
    {
      "name": "Christina Williams"
    },
    {
      "name": "Chris Willott"
    },
    {
      "name": "William Baker"
    },
    {
      "name": "Jacopo Chevallard"
    },
    {
      "name": "a Lola Danhaive"
    },
    {
      "name": "Yuki Isobe"
    },
    {
      "name": "Xihan Ji"
    },
    {
      "name": "Zhiyuan Ji"
    },
    {
      "name": "Gareth Jones"
    },
    {
      "name": "Nimisha Kumari"
    },
    {
      "name": "Tobias Looser"
    },
    {
      "name": "Jianwei Lyu"
    },
    {
      "name": "Eleonora Parlanti"
    },
    {
      "name": "Michele Perna"
    },
    {
      "name": "Dávid Puskás"
    },
    {
      "name": "Pierluigi Rinaldi"
    },
    {
      "name": "Charlotte Simmonds"
    },
    {
      "name": "Yang Sun"
    },
    {
      "name": "Hannah Übler"
    },
    {
      "name": "Giacomo Venturi"
    },
    {
      "name": "Joris Witstok"
    },
    {
      "name": "Zihao Wu"
    },
    {
      "name": "Yongda Zhu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4b7cnrpg84rnt.bib",
  "cited_by": 4,
  "doi": "10.1093/mnras/stag824",
  "fulltext_url": null,
  "id": "4b7cnrpg84rnt",
  "issns": [
    "0035-8711",
    "1365-2966"
  ],
  "landing_url": "https://hal.science/hal-05760816v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "1.phys.astr"
    ],
    [
      "hal",
      "2.phys.astr.co"
    ],
    [
      "openalex",
      "3105|Astronomy and Astrophysical Research"
    ]
  ],
  "openalex": "W7160021940",
  "pdf_url": "https://hal.science/hal-05760816/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-06-26",
  "publisher": "Oxford University Press (OUP): Policy P - Oxford Open Option A",
  "ris": "https://research.draconitic.com/paper/4b7cnrpg84rnt.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:43Z",
      "native_id": "hal-05760816",
      "source": "hal",
      "url": "https://hal.science/hal-05760816v1"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "hal:2.phys.astr.co",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "hal:0.phys",
      "subfield": "general"
    }
  ],
  "title": "JADES Dark Horse: demonstrating high-multiplex observations with JWST /NIRSpec dense-shutter spectroscopy in the JADES Origins Field",
  "title_text": "JADES Dark Horse: demonstrating high-multiplex observations with JWST /NIRSpec dense-shutter spectroscopy in the JADES Origins Field",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:43Z",
  "url": "https://research.draconitic.com/paper/4b7cnrpg84rnt",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}