_version_ 1866913163203575808
author D'Eugenio, Francesco
Nelson, Erica J.
Eisenstein, Daniel J.
Maiolino, Roberto
Carniani, Stefano
Scholtz, Jan
Curti, Mirko
Willmer, Christopher N. A.
Bunker, Andrew J.
Helton, Jakob M.
Juodžbalis, Ignas
Sun, Fengwu
Tacchella, Sandro
Arribas, Santiago
Cameron, Alex J.
Charlot, Stéphane
Curtis-Lake, Emma
Hainline, Kevin
Johnson, Benjamin D.
Robertson, Brant
Williams, Christina C.
Willott, Chris
Baker, William M.
Chevallard, Jacopo
Danhaive, A. Lola
Isobe, Yuki
Ji, Xihan
Ji, Zhiyuan
Jones, Gareth C.
Kumari, Nimisha
Looser, Tobias J.
Lyu, Jianwei
Parlanti, Eleonora
Perna, Michele
Puskás, Dávid
Rinaldi, Pierluigi
Simmonds, Charlotte
Sun, Yang
Übler, Hannah
Venturi, Giacomo
Witstok, Joris
Wu, Zihao
Zhu, Yongda
author_facet D'Eugenio, Francesco
Nelson, Erica J.
Eisenstein, Daniel J.
Maiolino, Roberto
Carniani, Stefano
Scholtz, Jan
Curti, Mirko
Willmer, Christopher N. A.
Bunker, Andrew J.
Helton, Jakob M.
Juodžbalis, Ignas
Sun, Fengwu
Tacchella, Sandro
Arribas, Santiago
Cameron, Alex J.
Charlot, Stéphane
Curtis-Lake, Emma
Hainline, Kevin
Johnson, Benjamin D.
Robertson, Brant
Williams, Christina C.
Willott, Chris
Baker, William M.
Chevallard, Jacopo
Danhaive, A. Lola
Isobe, Yuki
Ji, Xihan
Ji, Zhiyuan
Jones, Gareth C.
Kumari, Nimisha
Looser, Tobias J.
Lyu, Jianwei
Parlanti, Eleonora
Perna, Michele
Puskás, Dávid
Rinaldi, Pierluigi
Simmonds, Charlotte
Sun, Yang
Übler, Hannah
Venturi, Giacomo
Witstok, Joris
Wu, Zihao
Zhu, Yongda
contents We present JWST/NIRSpec dense-shutter spectroscopy (DSS). This novel observing strategy with the NIRSpec/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 (mF444W$<$30 mag) z$_\mathrm{phot}>$3 candidates, prioritising 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$540 galaxies over 2.5$<$z$<$8.9. The per-configuration target density in DSS mode is 4-5x higher than standard no- and low-overlap MSA strategies ($<$200 sources), with no loss in redshift precision or accuracy. Line-flux sensitivities are 30 percent lower at fixed exposure time, matching the expected increase in background noise, but the gain in survey speed is 5x in our setup, more than justifying the penalty. The measured line sensitivity exceeds NIRCam/WFSS by at least $\sim$5x ($\sim$25x in exposure time) at $λ\sim4\,μ$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 SFRs, gas-phase metallicities (including a large sample suitable for strong-line calibrations), and identify rare mini-quenched galaxies and broadline 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.
format Preprint
id arxiv_https___arxiv_org_abs_2510_11626
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle JADES Dark Horse: demonstrating high-multiplex observations with JWST/NIRSpec dense-shutter spectroscopy in the JADES Origins Field
D'Eugenio, Francesco
Nelson, Erica J.
Eisenstein, Daniel J.
Maiolino, Roberto
Carniani, Stefano
Scholtz, Jan
Curti, Mirko
Willmer, Christopher N. A.
Bunker, Andrew J.
Helton, Jakob M.
Juodžbalis, Ignas
Sun, Fengwu
Tacchella, Sandro
Arribas, Santiago
Cameron, Alex J.
Charlot, Stéphane
Curtis-Lake, Emma
Hainline, Kevin
Johnson, Benjamin D.
Robertson, Brant
Williams, Christina C.
Willott, Chris
Baker, William M.
Chevallard, Jacopo
Danhaive, A. Lola
Isobe, Yuki
Ji, Xihan
Ji, Zhiyuan
Jones, Gareth C.
Kumari, Nimisha
Looser, Tobias J.
Lyu, Jianwei
Parlanti, Eleonora
Perna, Michele
Puskás, Dávid
Rinaldi, Pierluigi
Simmonds, Charlotte
Sun, Yang
Übler, Hannah
Venturi, Giacomo
Witstok, Joris
Wu, Zihao
Zhu, Yongda
Astrophysics of Galaxies
Instrumentation and Methods for Astrophysics
We present JWST/NIRSpec dense-shutter spectroscopy (DSS). This novel observing strategy with the NIRSpec/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 (mF444W$<$30 mag) z$_\mathrm{phot}>$3 candidates, prioritising 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$540 galaxies over 2.5$<$z$<$8.9. The per-configuration target density in DSS mode is 4-5x higher than standard no- and low-overlap MSA strategies ($<$200 sources), with no loss in redshift precision or accuracy. Line-flux sensitivities are 30 percent lower at fixed exposure time, matching the expected increase in background noise, but the gain in survey speed is 5x in our setup, more than justifying the penalty. The measured line sensitivity exceeds NIRCam/WFSS by at least $\sim$5x ($\sim$25x in exposure time) at $λ\sim4\,μ$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 SFRs, gas-phase metallicities (including a large sample suitable for strong-line calibrations), and identify rare mini-quenched galaxies and broadline 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.
title JADES Dark Horse: demonstrating high-multiplex observations with JWST/NIRSpec dense-shutter spectroscopy in the JADES Origins Field
topic Astrophysics of Galaxies
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2510.11626