Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3

L. Barrufet; P. Oesch; R. Marques-Chaves; K. Arellano-Cordova; J. F. W. Baggen; A. C. Carnall; F. Cullen; J. S. Dunlop; R. Gottumukkala; Y. Fudamoto; G. D. Illingworth; D. Magee; R. J. McLure; D. J. McLeod; M. J. Michałowski; M. Stefanon; P. G. van Dokkum; A. Weibel

doi:10.1093/mnras/staf013

Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3

L. Barrufet^*, P. Oesch, R. Marques-Chaves, K. Arellano-Cordova, J. F. W. Baggen, A. C. Carnall, F. Cullen, J. S. Dunlop, R. Gottumukkala, Y. Fudamoto, G. D. Illingworth, D. Magee, R. J. McLure, D. J. McLeod, M. J. Michałowski, M. Stefanon, P. G. van Dokkum, A. Weibel

^*Corresponding author for this work

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

The advent of the JWST has revolutionised our understanding of high-redshift galaxies. In particular, the NIRCam instrument on-board JWST has revealed a population of red galaxies that had largely evaded detection with HST, potentially due to significant dust obscuration, quiescence, or extreme redshift. Here, we present the first NIRSpec spectra of 23 red, HST faint or dark galaxies galaxies (H − F444W > 1.75), unveiling their nature and physical properties. This sample includes both dusty and quiescent galaxies with spectroscopic data from NIRSpec/PRISM, providing accurate spectroscopic redshifts with zspec = 4.1 ± 0.7. The
spectral features demonstrate that, while the majority of red galaxies are dusty, a substantial fraction, 13+9−6%, are quiescent. For the dusty galaxies, we have quantified the dust attenuation using the Balmer decrement (Hα/Hβ), finding attenuations AV > 2 mag.
We find that red dusty galaxies are Hαemitters with equivalent widths spanning the range 68Å < EWHα < 550Å, indicative of a wide range of recent star-formation activity. Whether dusty or quiescent, we find that red galaxies are predominantly massive, with 85% of the galaxies in the sample having masses log(M∗/M⊙) > 9.8. This pilot NIRSpec program reveals the diverse nature of HST-dark galaxies and highlights the effectiveness of NIRSpec/PRISM spectroscopic follow-up in distinguishing between dusty and quiescent galaxies and properly quantifying their physical properties. Upcoming research utilising higher-resolution
NIRSpec data and combining JWST with ALMA observations will enhance our understanding of these enigmatic and challenging sources.

Original language	English
Pages (from-to)	3453-3469
Number of pages	17
Journal	Monthly Notices of the Royal Astronomical Society
Volume	537
Issue number	4
Early online date	7 Jan 2025
DOIs	https://doi.org/10.1093/mnras/staf013
Publication status	Published - 1 Mar 2025

Keywords / Materials (for Non-textual outputs)

Galaxies: high-redshift
Infrared: galaxies
Techniques: spectroscopic

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10.1093/mnras/staf013Licence: Creative Commons: Attribution (CC-BY)

https://arxiv.org/abs/2404.08052Licence: Creative Commons: Attribution (CC-BY)

Exploring the formation and growth of the first galaxies
Dunlop, J. (Principal Investigator)
Royal Society
31/03/23 → 30/03/28
Project: Research

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Barrufet, L., Oesch, P., Marques-Chaves, R., Arellano-Cordova, K., Baggen, J. F. W., Carnall, A. C., Cullen, F., Dunlop, J. S., Gottumukkala, R., Fudamoto, Y., Illingworth, G. D., Magee, D., McLure, R. J., McLeod, D. J., Michałowski, M. J., Stefanon, M., Dokkum, P. G. V., & Weibel, A. (2025). Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3. Monthly Notices of the Royal Astronomical Society , 537(4), 3453-3469. https://doi.org/10.1093/mnras/staf013

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title = "Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3",

abstract = "The advent of the JWST has revolutionised our understanding of high-redshift galaxies. In particular, the NIRCam instrument on-board JWST has revealed a population of red galaxies that had largely evaded detection with HST, potentially due to significant dust obscuration, quiescence, or extreme redshift. Here, we present the first NIRSpec spectra of 23 red, HST faint or dark galaxies galaxies (H − F444W > 1.75), unveiling their nature and physical properties. This sample includes both dusty and quiescent galaxies with spectroscopic data from NIRSpec/PRISM, providing accurate spectroscopic redshifts with zspec = 4.1 ± 0.7. Thespectral features demonstrate that, while the majority of red galaxies are dusty, a substantial fraction, 13+9−6%, are quiescent. For the dusty galaxies, we have quantified the dust attenuation using the Balmer decrement (Hα/Hβ), finding attenuations AV > 2 mag.We find that red dusty galaxies are Hαemitters with equivalent widths spanning the range 68{\AA} < EWHα < 550{\AA}, indicative of a wide range of recent star-formation activity. Whether dusty or quiescent, we find that red galaxies are predominantly massive, with 85% of the galaxies in the sample having masses log(M∗/M⊙) > 9.8. This pilot NIRSpec program reveals the diverse nature of HST-dark galaxies and highlights the effectiveness of NIRSpec/PRISM spectroscopic follow-up in distinguishing between dusty and quiescent galaxies and properly quantifying their physical properties. Upcoming research utilising higher-resolutionNIRSpec data and combining JWST with ALMA observations will enhance our understanding of these enigmatic and challenging sources.",

keywords = "Galaxies: high-redshift, Infrared: galaxies, Techniques: spectroscopic",

author = "L. Barrufet and P. Oesch and R. Marques-Chaves and K. Arellano-Cordova and Baggen, {J. F. W.} and Carnall, {A. C.} and F. Cullen and Dunlop, {J. S.} and R. Gottumukkala and Y. Fudamoto and Illingworth, {G. D.} and D. Magee and McLure, {R. J.} and McLeod, {D. J.} and Micha{\l}owski, {M. J.} and M. Stefanon and Dokkum, {P. G. van} and A. Weibel",

note = "13 pages, 11 figures",

year = "2025",

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doi = "10.1093/mnras/staf013",

language = "English",

volume = "537",

pages = "3453--3469",

journal = "Monthly Notices of the Royal Astronomical Society ",

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Barrufet, L, Oesch, P, Marques-Chaves, R, Arellano-Cordova, K, Baggen, JFW, Carnall, AC , Cullen, F , Dunlop, JS, Gottumukkala, R, Fudamoto, Y, Illingworth, GD, Magee, D, McLure, RJ, McLeod, DJ, Michałowski, MJ, Stefanon, M, Dokkum, PGV & Weibel, A 2025, 'Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3', Monthly Notices of the Royal Astronomical Society , vol. 537, no. 4, pp. 3453-3469. https://doi.org/10.1093/mnras/staf013

TY - JOUR

T1 - Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3

AU - Barrufet, L.

AU - Oesch, P.

AU - Marques-Chaves, R.

AU - Arellano-Cordova, K.

AU - Baggen, J. F. W.

AU - Carnall, A. C.

AU - Cullen, F.

AU - Dunlop, J. S.

AU - Gottumukkala, R.

AU - Fudamoto, Y.

AU - Illingworth, G. D.

AU - Magee, D.

AU - McLure, R. J.

AU - McLeod, D. J.

AU - Michałowski, M. J.

AU - Stefanon, M.

AU - Dokkum, P. G. van

AU - Weibel, A.

N1 - 13 pages, 11 figures

PY - 2025/3/1

Y1 - 2025/3/1

N2 - The advent of the JWST has revolutionised our understanding of high-redshift galaxies. In particular, the NIRCam instrument on-board JWST has revealed a population of red galaxies that had largely evaded detection with HST, potentially due to significant dust obscuration, quiescence, or extreme redshift. Here, we present the first NIRSpec spectra of 23 red, HST faint or dark galaxies galaxies (H − F444W > 1.75), unveiling their nature and physical properties. This sample includes both dusty and quiescent galaxies with spectroscopic data from NIRSpec/PRISM, providing accurate spectroscopic redshifts with zspec = 4.1 ± 0.7. Thespectral features demonstrate that, while the majority of red galaxies are dusty, a substantial fraction, 13+9−6%, are quiescent. For the dusty galaxies, we have quantified the dust attenuation using the Balmer decrement (Hα/Hβ), finding attenuations AV > 2 mag.We find that red dusty galaxies are Hαemitters with equivalent widths spanning the range 68Å < EWHα < 550Å, indicative of a wide range of recent star-formation activity. Whether dusty or quiescent, we find that red galaxies are predominantly massive, with 85% of the galaxies in the sample having masses log(M∗/M⊙) > 9.8. This pilot NIRSpec program reveals the diverse nature of HST-dark galaxies and highlights the effectiveness of NIRSpec/PRISM spectroscopic follow-up in distinguishing between dusty and quiescent galaxies and properly quantifying their physical properties. Upcoming research utilising higher-resolutionNIRSpec data and combining JWST with ALMA observations will enhance our understanding of these enigmatic and challenging sources.

AB - The advent of the JWST has revolutionised our understanding of high-redshift galaxies. In particular, the NIRCam instrument on-board JWST has revealed a population of red galaxies that had largely evaded detection with HST, potentially due to significant dust obscuration, quiescence, or extreme redshift. Here, we present the first NIRSpec spectra of 23 red, HST faint or dark galaxies galaxies (H − F444W > 1.75), unveiling their nature and physical properties. This sample includes both dusty and quiescent galaxies with spectroscopic data from NIRSpec/PRISM, providing accurate spectroscopic redshifts with zspec = 4.1 ± 0.7. Thespectral features demonstrate that, while the majority of red galaxies are dusty, a substantial fraction, 13+9−6%, are quiescent. For the dusty galaxies, we have quantified the dust attenuation using the Balmer decrement (Hα/Hβ), finding attenuations AV > 2 mag.We find that red dusty galaxies are Hαemitters with equivalent widths spanning the range 68Å < EWHα < 550Å, indicative of a wide range of recent star-formation activity. Whether dusty or quiescent, we find that red galaxies are predominantly massive, with 85% of the galaxies in the sample having masses log(M∗/M⊙) > 9.8. This pilot NIRSpec program reveals the diverse nature of HST-dark galaxies and highlights the effectiveness of NIRSpec/PRISM spectroscopic follow-up in distinguishing between dusty and quiescent galaxies and properly quantifying their physical properties. Upcoming research utilising higher-resolutionNIRSpec data and combining JWST with ALMA observations will enhance our understanding of these enigmatic and challenging sources.

KW - Galaxies: high-redshift

KW - Infrared: galaxies

KW - Techniques: spectroscopic

U2 - 10.1093/mnras/staf013

DO - 10.1093/mnras/staf013

M3 - Article

SN - 0035-8711

VL - 537

SP - 3453

EP - 3469

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 4

ER -

Quiescent or dusty? Unveiling the nature of extremely red galaxies at z>3

Abstract

Keywords / Materials (for Non-textual outputs)

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Projects

Exploring the formation and growth of the first galaxies

Cite this