CaltechAUTHORS
Published February 1, 2023 | Version Published
Journal Article Open

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

Creators

  • 1. ROR icon National Astronomical Observatory of Japan
  • 2. ROR icon French National Centre for Scientific Research
  • 3. ROR icon The University of Texas at Austin
  • 4. ROR icon University of Paris
  • 5. ROR icon NOIRLab
  • 6. ROR icon Space Telescope Science Institute
  • 7. ROR icon National Autonomous University of Mexico
  • 8. ROR icon Rochester Institute of Technology
  • 9. ROR icon National Radio Astronomy Observatory
  • 10. ROR icon Texas A&M University
  • 11. ROR icon University of Cambridge
  • 12. ROR icon University of Sussex
  • 13. ROR icon University of Malta
  • 14. ROR icon National Institute of Astrophysics, Optics and Electronics
  • 15. ROR icon University of Arizona
  • 16. ROR icon Astronomical Observatory of Rome
  • 17. ROR icon University of Massachusetts Amherst
  • 18. ROR icon Osservatorio Astronomico di Padova
  • 19. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 20. ROR icon Colby College
  • 21. ROR icon University of Kansas
  • 22. ROR icon Centro de Astrobiología
  • 23. ROR icon University of Connecticut
  • 24. ROR icon University of Groningen
  • 25. ROR icon Netherlands Institute for Space Research
  • 26. ROR icon University of Nottingham
  • 27. ROR icon University of La Serena
  • 28. ROR icon University of the Pacific
  • 29. ROR icon University of Michigan–Ann Arbor
  • 30. ROR icon European Space Research and Technology Centre
  • 31. ROR icon University of Padua
  • 32. ROR icon University of Valladolid
  • 33. ROR icon University of Lisbon
  • 34. ROR icon Arizona State University
  • 35. ROR icon American Association For The Advancement of Science
  • 36. ROR icon University of California, Berkeley
  • 37. ROR icon Swinburne University of Technology
  • 38. ROR icon Centre of Excellence for All-Sky Astrophysics
  • 39. ROR icon University of Edinburgh
  • 40. ROR icon University of the Western Cape
  • 41. ROR icon Johns Hopkins University
  • 42. ROR icon Hebrew University of Jerusalem
  • 43. ROR icon Saint Mary's University
  • 44. ROR icon Observatory of Strasbourg
  • 45. ROR icon University of Copenhagen
  • 46. ROR icon Complutense University of Madrid
  • 47. ROR icon Rutgers, The State University of New Jersey
  • 48. ROR icon Shawnee State University
  • 49. ROR icon University of Louisville
  • 50. ROR icon École Polytechnique Fédérale de Lausanne
  • 51. ROR icon Instituto de Astrofísica de Canarias
  • 52. ROR icon University of La Laguna
  • 53. ROR icon University of Toronto
  • 54. ROR icon Williams College
  • 55. ROR icon Catholic University of America
  • 56. ROR icon Goddard Space Flight Center
  • 57. ROR icon University of Minnesota
  • 58. ROR icon University of Missouri–Kansas City
  • 59. ROR icon University of California, Riverside
  • 60. ROR icon University of Pittsburgh
  • 61. ROR icon Australian National University
  • 62. ROR icon Columbia University
  • 63. ROR icon University of California, Davis
  • 64. ROR icon University of Science and Technology of China
  • 65. ROR icon University of Warwick
  • 66. ROR icon Infrared Processing and Analysis Center
  • 67. ROR icon University of Bath

Abstract

Lyman-break galaxy (LBG) candidates at z ≳ 10 are rapidly being identified in James Webb Space Telescope (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 2.6σ SCUBA-2 detection at 850 μm 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.

Additional Information

© 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. We thank the reviewer for a constructive report that improved the clarity of our results. We also thank Jim Dunlop for helpful discussions. V.B. and D.B. thank the Programme National de Cosmologie et Galaxies and CNES for their support. We thank Médéric Boquien and Yannick Roehlly for their help. C.M.C. thanks the National Science Foundation for support through grants AST-1814034 and AST-2009577 and additionally the Research Corporation for Science Advancement from a 2019 Cottrell Scholar Award sponsored by IF/THEN, an initiative of Lyda Hill Philanthropies. I.A. acknowledges support from CONACyT CB-382947. We acknowledge support from STScI through award JWST-ERS-1345. This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with program #1345 and can be accessed in a raw format via doi:10.17909/4abm-k128. This work is based on observations carried out under project number W20CK with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain). Facilities: JWST - James Webb Space Telescope, NOEMA - , JCMT. -

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Additional details

Identifiers

Eprint ID
120003
Resolver ID
CaltechAUTHORS:20230314-844891400.17

Funding

Programme National de Cosmologie et Galaxies (PNCG)
Centre National d'Études Spatiales (CNES)
NSF
AST-1814034
NSF
AST-2009577
Cottrell Scholar of Research Corporation
Consejo Nacional de Ciencia y Tecnología (CONACYT)
CB-382947
NASA
JWST-ERS-1345
NASA
NAS 5-03127

Dates

Created
2023-05-16
Created from EPrint's datestamp field
Updated
2023-05-16
Created from EPrint's last_modified field

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Infrared Processing and Analysis Center (IPAC)