A population of red candidate massive galaxies ~600 Myr after the Big Bang

Labbé, Ivo; Dokkum, Pieter van; Nelson, Erica J.; Bezanson, Rachel; Suess, Katherine A.; Leja, Joel; Brammer, Gabriel; Whitaker, Katherine E.; Mathews, Elijah; Stefanon, Mauro; Wang, Bingjie

doi:10.1038/s41586-023-05786-2

“…To conclude, high-z surveys in the era of JWST increasingly require us to infer more physical information from lessinformative data. Applying Prospector-β to early JWST observations will downweight solutions that are disfavored by current observational constraints on galaxy formation, and hence increase our confidence in the results of our fitting (e.g., Labbe et al 2022;Nelson et al 2022).…”

Section: Discussionmentioning

confidence: 99%

“…The nearest-neighbor choice may be favored in the absence of reliable high-resolution restframe optical selected mass functions at z > 3. Importantly, it allots a conservatively high probability for yet-to-be-discovered populations of high-mass, high-z galaxies, hints of which have already been observed in Labbe et al (2022).…”

Section: Stellar Mass Functionmentioning

confidence: 99%

Inferring More from Less: Prospector as a Photometric Redshift Engine in the Era of JWST

Wang

¹

,

Leja

²

,

Bezanson

³

et al. 2023

ApJL

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The advent of the James Webb Space Telescope (JWST) signals a new era in exploring galaxies in the high-z universe. Current and upcoming JWST imaging will potentially detect galaxies at z ∼ 20, creating a new urgency in the quest to infer accurate photometric redshifts (photo-z) for individual galaxies from their spectral energy distributions, as well as masses, ages, and star formation rates. Here we illustrate the utility of informed priors encoding previous observations of galaxies across cosmic time in achieving these goals. We construct three joint priors encoding empirical constraints of redshifts, masses, and star formation histories in the galaxy population within the Prospector Bayesian inference framework. In contrast with uniform priors, our model breaks an age–mass–redshift degeneracy, and thus reduces the mean bias error in masses from 0.3 to 0.1 dex, and in ages from 0.6 to 0.2 dex in tests done on mock JWST observations. Notably, our model recovers redshifts at least as accurately as the state-of-the-art photo-z code EAzY in deep JWST fields, but with two advantages: tailoring a model based on a particular survey is rendered mostly unnecessary given well-motivated priors; obtaining joint posteriors describing stellar, active galactic nuclei, gas, and dust contributions becomes possible. We can now confidently use the joint distribution to propagate full non-Gaussian redshift uncertainties into inferred properties of the galaxy population. This model, “Prospector-β,” is intended for fitting galaxy photometry where the redshift is unknown, and will be instrumental in ensuring the maximum science return from forthcoming photometric surveys with JWST. The code is made publicly available online as a part of Prospector 9 9 The version used in this work corresponds to the state of the Git repository at commit https://github.com/bd-j/prospector/commit/820ad72363a1f9c22cf03610bfe6e361213385cd. .

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“…The cosmological importance of HST-dark galaxies to improve our knowledge about galaxy evolution is not negligible. The existence of a numerous population of massive galaxies already in place or even evolving passively at z > 2-3, and even up to z ∼ 6 (and beyond; see Barrufet et al 2022;Endsley et al 2022;Labbe et al 2022;Nelson et al 2022;Tacchella et al 2022a), is very difficult to reproduce by stateof-the-art galaxy evolution models (see discussion in Alcalde Pampliega et al 2019 and the recent discussion on JWST results in Lovell et al 2023), which also suffer from their limitations in area to understand the nature of these samples presenting relatively small volume densities.…”

Section: Introductionmentioning

confidence: 99%

CEERS Key Paper. IV. A Triality in the Nature of HST-dark Galaxies

Pérez‐González

¹

,

Barro

²

,

Annunziatella

³

et al. 2023

ApJL

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The new capabilities that JWST offers in the near- and mid-infrared (IR) are used to investigate in unprecedented detail the nature of optical/near-IR-faint, mid-IR-bright sources, with HST-dark galaxies among them. We gather JWST data from the CEERS survey in the Extended Groth Strip, jointly with HST data, and analyze spatially resolved optical-to-mid-IR spectral energy distributions to estimate photometric redshifts in two dimensions and stellar population properties on a pixel-by-pixel basis for red galaxies detected by NIRCam. We select 138 galaxies with F150W − F356W > 1.5 mag and F356W < 27.5 mag. The nature of these sources is threefold: (1) 71% are dusty star-forming galaxies (SFGs) at 2 < z < 6 with 9 < log M ⋆ / M ⊙ < 11 and a variety of specific SFRs (<1 to >100 Gyr−1); (2) 18% are quiescent/dormant (i.e., subject to reignition/rejuvenation) galaxies (QGs) at 3 < z < 5, with log M ⋆ / M ⊙ ∼ 10 and poststarburst mass-weighted ages (0.5–1.0 Gyr); and (3) 11% are strong young starbursts with indications of high equivalent width emission lines (typically, [O iii]+Hβ) at 6 < z < 7 (XELG-z6) and log M ⋆ / M ⊙ ∼ 9.5 . The sample is dominated by disk-like galaxies with remarkable compactness for XELG-z6 (effective radii smaller than 0.4 kpc). Large attenuations in SFGs, 2 < A(V) < 5 mag, are found within 1.5 times the effective radius, approximately 2 kpc, while QGs present A(V) ∼ 0.2 mag. Our SED-fitting technique reproduces the expected dust emission luminosities of IR-bright and submillimeter galaxies. This study implies high levels of star formation activity between z ∼ 20 and z ∼ 10, where virtually 100% of our galaxies had already formed 108 M ⊙, 60% had assembled 109 M ⊙, and 10% up to 1010 M ⊙ (in situ or ex situ).

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“…Recently, a growing number of NIR faint galaxies have been identified in early JWST data (Barrufet et al 2022;Carnall et al 2023;Iani et al 2022;Labbe et al 2022;Nelson et al 2022). A few HST-dark galaxies were identified as dusty red spiral galaxies at cosmic noon (Fudamoto et al 2022).…”

Section: Introductionmentioning

confidence: 99%

JWST Insight into a Lensed HST-dark Galaxy and Its Quiescent Companion at z = 2.58

Kokorev

¹

,

Jin

²

,

Magdis

³

et al. 2023

ApJL

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Using the novel James Webb Space Telescope (JWST)/NIRCam observations in the A2744 field, we present a first spatially resolved overview of a Hubble Space Telescope (HST)-dark galaxy, spectroscopically confirmed at z = 2.58 with magnification μ ≈ 1.9. While being largely invisible at ∼1 μm with NIRCam, except for sparse clumpy substructures, the object is well detected and resolved in the long-wavelength bands with a spiral shape clearly visible in F277W. By combining ancillary Atacama Large Millimeter/submillimeter Array (ALMA) and Herschel data, we infer that this object is an edge-on dusty spiral with an intrinsic stellar mass log (M */M ⊙) ∼ 11.3 and a dust-obscured star formation rate ∼300 M ⊙ yr−1. A massive quiescent galaxy (log (M */M ⊙) ∼ 10.8) with tidal features lies 2.″0 away (r ∼ 9 kpc), at a consistent redshift as inferred by JWST photometry, indicating a potential major merger. The dusty spiral lies on the main sequence of star formation, and shows high dust attenuation in the optical (3 < A V < 4.5). In the far-infrared, its integrated dust spectral energy distribution is optically thick up to λ 0 ∼ 500 μm, further supporting the extremely dusty nature. Spatially resolved analysis of the HST-dark galaxy reveals a largely uniform A V ∼ 4 area spanning ∼57 kpc2, which spatially matches to the ALMA 1 mm continuum emission. Accounting for the surface brightness dimming and the depths of current JWST surveys, unlensed analogs of the HST-dark galaxy at z > 4 would be only detectable in F356W and F444W in an UNCOVER-like survey, and become totally JWST-dark at z ∼ 6. This suggests that detecting highly attenuated galaxies in the Epoch of Reionization might be a challenging task for JWST.

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A population of red candidate massive galaxies ~600 Myr after the Big Bang

Cited by 232 publications

References 64 publications

Inferring More from Less: Prospector as a Photometric Redshift Engine in the Era of JWST

Inferring More from Less: Prospector as a Photometric Redshift Engine in the Era of JWST

CEERS Key Paper. IV. A Triality in the Nature of HST-dark Galaxies

JWST Insight into a Lensed HST-dark Galaxy and Its Quiescent Companion at z = 2.58

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