UNCOVER: A NIRSpec Census of Lensed Galaxies at z = 8.50–13.08 Probing a High-AGN Fraction and Ionized Bubbles in the Shadow
Abstract We present JWST NIRSpec prism spectroscopy of lensed galaxies at z ≳ 9 found behind the massive galaxy cluster Abell 2744 in the UNCOVER Cycle 1 Treasury Program. We confirm the redshift via emission lines and/or the Ly α break for 10 galaxies at z = 8.50–13.08 down to M V = −17.3. We achieve a 100% confirmation rate for z > 9 candidates reported in H. Atek et al. Using six sources with multiple line detections, we find that offsets in redshift estimates between the lines and the Ly α break alone can be ±0.2, raising caution in designing future follow-up spectroscopy for the break-only sources with the Atacama Large Millimeter/submillimeter Array. With spec- z -confirmed sources in UNCOVER and the literature, we derive lower limits on the rest-frame ultraviolet (UV) luminosity function (LF) at z ≃ 9–12 and find that these lower limits agree with recent photometric measurements. We identify at least two unambiguous and several possible active galactic nucleus (AGN) systems based on X-ray, broad H β , high ionization lines, and excess in the UV LF. This requires the AGN LFs at z ≃ 9–10 to be comparable or even higher than the X-ray AGN LF estimated at z ∼ 6 and suggests a plausible cause of the high abundance of z > 9 galaxies claimed in the recent photometric measurements is AGNs. One UV-luminous source is confirmed at the same redshift as a broad-line AGN at z = 8.50 with a physical separation of 380 kpc in the source plane. These two sources show emission blueward of Ly α , indicating a giant ionized bubble enclosing them with a radius of 7.69 ± 0.18 pMpc. Our results imply that AGNs have a nonnegligible contribution to cosmic reionization.
Authors
- Pratika Dayal (ORCID: https://orcid.org/0000-0001-8460-1564)
- Seiji Fujimoto (ORCID: https://orcid.org/0000-0001-7201-5066)
- Lukas J. Furtak (ORCID: https://orcid.org/0000-0001-6278-032X)
- Rachel Bezanson (ORCID: https://orcid.org/0000-0001-5063-8254)
- Danilo Marchesini (ORCID: https://orcid.org/0000-0001-9002-3502)
- Gourav Khullar (ORCID: https://orcid.org/0000-0002-3475-7648)
- Vasily Kokorev (ORCID: https://orcid.org/0000-0002-5588-9156)
- Tim B. Miller (ORCID: https://orcid.org/0000-0001-8367-6265)
- Sam E. Cutler (ORCID: https://orcid.org/0000-0002-7031-2865)
- Richard Pan (ORCID: https://orcid.org/0000-0002-9651-5716)
- Jenny E. Greene (ORCID: https://orcid.org/0000-0002-5612-3427)
- Ivo Labbé (ORCID: https://orcid.org/0000-0002-2057-5376)
- Mauro Stefanon (ORCID: https://orcid.org/0000-0001-7768-5309)
- Themiya Nanayakkara (ORCID: https://orcid.org/0000-0003-2804-0648)
- Dan Coe (ORCID: https://orcid.org/0000-0001-7410-7669)
- John R. Weaver (ORCID: https://orcid.org/0000-0003-1614-196X)
- David J. Setton (ORCID: https://orcid.org/0000-0003-4075-7393)
- Christina C. Williams (ORCID: https://orcid.org/0000-0003-2919-7495)
- Andy D. Goulding (ORCID: https://orcid.org/0000-0003-4700-663X)
- Robert Feldmann (ORCID: https://orcid.org/0000-0002-1109-1919)
- Yoshinobu Fudamoto (ORCID: https://orcid.org/0000-0001-7440-8832)
- Joel Leja (ORCID: https://orcid.org/0000-0001-6755-1315)
- Pieter van Dokkum (ORCID: https://orcid.org/0000-0002-8282-9888)
- Iryna Chemerynska (ORCID: https://orcid.org/0009-0009-9795-6167)
- Hakim Atek (ORCID: https://orcid.org/0000-0002-7570-0824)
- Erica J. Nelson (ORCID: https://orcid.org/0000-0002-7524-374X)
- Pascal A. Oesch (ORCID: https://orcid.org/0000-0001-5851-6649)
- Gabriel Brammer (ORCID: https://orcid.org/0000-0003-2680-005X)
- Michael V. Maseda (ORCID: https://orcid.org/0000-0003-0695-4414)
- Katherine E. Whitaker (ORCID: https://orcid.org/0000-0001-7160-3632)
- Adi Zitrin (ORCID: https://orcid.org/0000-0002-0350-4488)
- Renske Smit (ORCID: https://orcid.org/0000-0001-8034-7802)
- Sedona H. Price (ORCID: https://orcid.org/0000-0002-0108-4176)
- Andrea Weibel (ORCID: https://orcid.org/0000-0001-8928-4465)
- Anna de Graaff (ORCID: https://orcid.org/0000-0002-2380-9801)
- Bingjie Wang (ORCID: https://orcid.org/0000-0001-9269-5046)
Institutions
- Institut d'Astrophysique de Paris (FR)
- European Space Agency (FR)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-12-01
- DOI
- https://doi.org/10.3847/1538-4357/ad9027
- Citations
- 35
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 11.60
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- Space Telescope Science Institute
- European Commission
- National Research Foundation
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Rijksuniversiteit Groningen
- Danmarks Grundforskningsfond
- United States-Israel Binational Science Foundation
- Centre National d’Etudes Spatiales
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek
- Generalitat Valenciana
- Centre National de la Recherche Scientifique
- Ministerio de Ciencia e Innovación
- Science and Technology Facilities Council
- Staatssekretariat für Bildung, Forschung und Innovation
- Agencia Estatal de Investigación
- Institut National de Physique Nucléaire et de Physique des Particules