Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations

Abstract

Lyman Break Galaxy (LBG) candidates at z>10 are rapidly being identified in JWST/NIRCam observations. Due to the (redshifted) break produced by neutral hydrogen absorption of rest-frame UV photons, these sources are expected to drop out in the bluer filters while being well detected in redder filters. However, here we show that dust-enshrouded star-forming galaxies at lower redshifts (z<7) may also mimic the near-infrared (near-IR) colors of z>10 LBGs, representing potential contaminants in LBG candidate samples. First, we analyze CEERS-DSFG-1, a NIRCam dropout undetected in the F115W and F150W filters but detected at longer wavelengths. Combining the JWST data with (sub)millimeter constraints, including deep NOEMA interferometric observations, we show that this source is a dusty star-forming galaxy (DSFG) at z~5.1. We also present a tentative 2.6sigma SCUBA-2 detection at 850um around a recently identified z~16 LBG candidate in the same field and show that, if the emission is real and associated with this candidate, the available photometry is consistent with a z~5 dusty galaxy with strong nebular emission lines despite its blue near-IR colors. Further observations on this candidate are imperative to mitigate the low confidence of this tentative submillimeter emission and its positional uncertainty. Our analysis shows that robust (sub)millimeter detections of NIRCam dropout galaxies likely imply z=4-6 redshift solutions, where the observed near-IR break would be the result of a strong rest-frame optical Balmer break combined with high dust attenuation and strong nebular line emission, rather than the rest-frame UV Lyman break. This provides evidence that DSFGs may contaminate searches for ultra high-redshift LBG candidates from JWST observations.

Published in The Astrophysical Journal Letters (updated to match the published version)

References in corpus (32)

• EAZY: A Fast, Public Photometric Redshift Code
• An ALMA survey of Sub-millimeter Galaxies in the Extended Chandra Deep Field South: Physical properties derived from ultraviolet-to-radio modelling
• The evolution of the galaxy UV luminosity function at redshifts z ~ 8-15 from deep JWST and ground-based near-infrared imaging
• A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
• Early results from GLASS-JWST. III: Galaxy candidates at z$\sim$9-15
• Dust in the reionization era: ALMA observations of a $z$=8.38 Galaxy
• The 0.4 < z < 1.3 star formation history of the Universe as viewed in the far-infrared
• Discovery and properties of ultra-high redshift galaxies ($9<z<12$) in the JWST ERO SMACS 0723 Field
• A dominant population of optically invisible massive galaxies in the early Universe
• Galaxy growth in a massive halo in the first billion years of cosmic history
• Revealing Galaxy Candidates out to $z\sim 16$ with JWST Observations of the Lensing Cluster SMACS0723
• Galaxy Formation and Reionization: Key Unknowns and Expected Breakthroughs by the James Webb Space Telescope
• Are Dusty Galaxies Blue? Insights on UV Attenuation from Dust-Selected Galaxies
• ALMA uncovers the [CII] emission and warm dust continuum in a z = 8.31 Lyman break galaxy
• The ALMA Spectroscopic Survey Large Program: The Infrared Excess of z=1.5-10 UV-selected Galaxies and the Implied High-Redshift Star Formation History
• Extreme Value Statistics of the Halo and Stellar Mass Distributions at High Redshift: are JWST Results in Tension with ΛCDM?
• ISM properties of a Massive Dusty Star-Forming Galaxy discovered at z ~ 7
• The REBELS ALMA Survey: cosmic dust temperature evolution out to z $\sim$ 7
• The ALMA REBELS Survey: Dust Continuum Detections at z > 6.5
• First Batch of Candidate Galaxies at Redshifts 11 to 20 Revealed by the James Webb Space Telescope Early Release Observations
• Are high redshift Galaxies hot? - Temperature of z > 5 Galaxies and Implications on their Dust Properties
• The ALPINE-ALMA [CII] Survey: Obscured Star Formation Rate Density and Main Sequence of star-forming galaxies at z>4
• The SCUBA HAlf Degree Extragalactic Survey (SHADES) - VII. Optical/IR photometry and stellar masses of sub-millimeter galaxies
• A systematic search for very massive galaxies at z > 4
• Mapping Obscuration to Reionization with ALMA (MORA): 2mm Efficiently Selects the Highest-Redshift Obscured Galaxies
• The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field: The nature of the faintest dusty star-forming galaxies
• The SCUBA-2 Cosmology Legacy Survey: The EGS deep field I - Deep number counts and the redshift distribution of the recovered Cosmic Infrared Background at 450 and 850 um
• GOODS-ALMA 2.0: Starbursts in the main sequence reveal compact star formation regulating galaxy evolution prequenching
• Dust formation, evolution, and obscuration effects in the very high-redshift universe
• No Redshift Evolution of Dust Temperatures from $0<z<2$
• Far-Infrared Photometric Redshifts: A New Approach to a Highly Uncertain Enterprise
• The SCUBA-2 Cosmology Legacy Survey: The EGS deep field -- III. The evolution of faint submillimeter galaxies at $z<4$

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• JWST UNCOVER: The Overabundance of Ultraviolet-luminous Galaxies at $z>9$
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• A physically-motivated template set for high-z galaxy SED fitting
• The Evolution of the SFR-M_* relation at 0.1<z<4: Environmental and Morphological Dependencies
• Uncertainty-Aware Neural Networks for Fuzzy Dark Matter Model Selection from \texorpdfstring{$x_{\mathrm{HI}}$}{x_HI} Measurements