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Published October 20, 2022 | Version Published
Journal Article Open

Early Results from GLASS-JWST. I: Confirmation of Lensed z ≥ 7 Lyman-break Galaxies behind the Abell 2744 Cluster with NIRISS

Creators

  • 1. ROR icon University of California, Los Angeles
  • 2. ROR icon Infrared Processing and Analysis Center
  • 3. ROR icon University of Copenhagen
  • 4. ROR icon University of Ljubljana
  • 5. ROR icon University of California, Davis
  • 6. ROR icon University of Milan
  • 7. ROR icon Istituto di Astrofisica Spaziale e Fisica Cosmica di Milano
  • 8. ROR icon University of Melbourne
  • 9. ROR icon Centre of Excellence for All-Sky Astrophysics
  • 10. ROR icon Astronomical Observatory of Rome
  • 11. ROR icon Swinburne University of Technology
  • 12. ROR icon Space Telescope Science Institute
  • 13. ROR icon Johns Hopkins University
  • 14. ROR icon Tufts University
  • 15. ROR icon Astronomical Observatory of Capodimonte
  • 16. ROR icon University of Ferrara
  • 17. ROR icon University of Minnesota
  • 18. ROR icon Osservatorio Astronomico di Padova

Abstract

We present the first search for z ≥ 7, continuum-confirmed Lyman break sources with NIRISS/WFS spectroscopy over the Abell 2744 Frontier Fields cluster, as part of the GLASS-JWST-ERS survey. With ∼15 hr of preimaging and multiangle grism exposures in the F115W, F150W, and F200W filters, we describe the general data handling (i.e., reduction, cleaning, modeling, and extraction processes) and analysis for the GLASS-JWST survey. We showcase the power of JWST to peer deep into reionization, when most intergalactic hydrogen is neutral, by confirming two galaxies at z = 8.04 ± 0.15 and z = 7.90 ± 0.13 by means of their Lyman breaks. Fainter continuum spectra are observed in both the F150W and F200W bands, indicative of blue (−1.69 and −1.33) UV slopes and moderately bright absolute magnitudes (−20.37 and −19.68 mag). We do not detect strong Lyα in either galaxy, but do observe tentative (∼2.7–3.8σ) He ɪɪλ1640 Å, O ɪɪɪ]λλ1661,1666 Å, and N ɪɪɪ]λλ1747,1749 Å line emission in one, suggestive of low-metallicity, star-forming systems with possible nonthermal contributions. These novel observations provide a first look at the extraordinary potential of JWST/NIRISS for confirming representative samples of bright z ≥ 7 sources in the absence of strong emission lines, and gain unprecedented insight into their contributions toward cosmic reionization.

Additional Information

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 JWST-ERS-1324. We acknowledge financial support from NASA through grant JWST-ERS-1324. K.G. and T.N. acknowledge support from Australian Research Council Laureate Fellowship FL180100060. C.M. acknowledges support by the VILLUM FONDEN under grant 37459. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant DNRF140. M.B. acknowledges support from the Slovenian national research agency ARRS through grant N1-0238. This research is supported in part by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project No. CE170100013. We acknowledge financial support through grants PRIN-MIUR 2017WSCC32 and 2020SKSTHZ.

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Additional details

Identifiers

Eprint ID
117667
Resolver ID
CaltechAUTHORS:20221031-575177800.31

Funding

NASA
NAS 5-03127
NASA
JWST-ERS-1324
Australian Research Council
FL180100060
Villum Foundation
37459
Danish National Research Foundation
DNRF140
ARRS
N1-0238
Australian Research Council
CE170100013
Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)
2017WSCC32
Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)
2020SKSTHZ

Dates

Created
2022-11-09
Created from EPrint's datestamp field
Updated
2022-11-11
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC)