JADES Dark Horse: demonstrating high-multiplex observations with JWST /NIRSpec dense-shutter spectroscopy in the JADES Origins Field

@article{deugenio2026jades,
  title = {{JADES Dark Horse: demonstrating high-multiplex observations with JWST /NIRSpec dense-shutter spectroscopy in the JADES Origins Field}},
  author = {Francesco D’eugenio and Erica Nelson and Daniel Eisenstein and Roberto Maiolino and Stefano Carniani and Jan Scholtz and Mirko Curti and Christopher Willmer and Andrew Bunker and Jakob Helton and Ignas Juodžbalis and Fengwu Sun and Sandro Tacchella and Santiago Arribas and Alex Cameron and Stéphane Charlot and Emma Curtis-Lake and Kevin Hainline and Benjamin Johnson and Brant Robertson and Christina Williams and Chris Willott and William Baker and Jacopo Chevallard and a Lola Danhaive and Yuki Isobe and Xihan Ji and Zhiyuan Ji and Gareth Jones and Nimisha Kumari and Tobias Looser and Jianwei Lyu and Eleonora Parlanti and Michele Perna and Dávid Puskás and Pierluigi Rinaldi and Charlotte Simmonds and Yang Sun and Hannah Übler and Giacomo Venturi and Joris Witstok and Zihao Wu and Yongda Zhu},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2026},
  month = jun,
  doi = {10.1093/mnras/stag824},
  eprint = {2510.11626},
  archivePrefix = {arXiv},
  url = {https://hal.science/hal-05760816v1},
  note = {CC BY 4.0},
}

TY  - JOUR
TI  - JADES Dark Horse: demonstrating high-multiplex observations with JWST /NIRSpec dense-shutter spectroscopy in the JADES Origins Field
AU  - Francesco D’eugenio
AU  - Erica Nelson
AU  - Daniel Eisenstein
AU  - Roberto Maiolino
AU  - Stefano Carniani
AU  - Jan Scholtz
AU  - Mirko Curti
AU  - Christopher Willmer
AU  - Andrew Bunker
AU  - Jakob Helton
AU  - Ignas Juodžbalis
AU  - Fengwu Sun
AU  - Sandro Tacchella
AU  - Santiago Arribas
AU  - Alex Cameron
AU  - Stéphane Charlot
AU  - Emma Curtis-Lake
AU  - Kevin Hainline
AU  - Benjamin Johnson
AU  - Brant Robertson
AU  - Christina Williams
AU  - Chris Willott
AU  - William Baker
AU  - Jacopo Chevallard
AU  - a Lola Danhaive
AU  - Yuki Isobe
AU  - Xihan Ji
AU  - Zhiyuan Ji
AU  - Gareth Jones
AU  - Nimisha Kumari
AU  - Tobias Looser
AU  - Jianwei Lyu
AU  - Eleonora Parlanti
AU  - Michele Perna
AU  - Dávid Puskás
AU  - Pierluigi Rinaldi
AU  - Charlotte Simmonds
AU  - Yang Sun
AU  - Hannah Übler
AU  - Giacomo Venturi
AU  - Joris Witstok
AU  - Zihao Wu
AU  - Yongda Zhu
PY  - 2026
DA  - 2026/06/26
JO  - Monthly Notices of the Royal Astronomical Society
DO  - 10.1093/mnras/stag824
UR  - https://hal.science/hal-05760816v1
AB  - 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_F444Wlt 30 mag) z_photgt 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 ∼850 sources, obtaining spectroscopic redshifts for ∼540 galaxies over 2.5≲ z ≲ 8.9. The per-configuration target density in DSS mode is 4–5× 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× in our setup, more than justifying the penalty. The measured line sensitivity exceeds NIRCam slitless spectroscopy by at least ∼ 5× (∼ 25× in exposure time) at λ ∼ 4 μ 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.
SN  - 0035-8711
SN  - 1365-2966
ER  -