Issue |
A&A
Volume 693, January 2025
|
|
---|---|---|
Article Number | A50 | |
Number of page(s) | 17 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202452090 | |
Published online | 03 January 2025 |
Seven wonders of Cosmic Dawn: JWST confirms a high abundance of galaxies and AGN at z ≃ 9–11 in the GLASS field
1
INAF – Osservatorio Astronomico di Roma, via Frascati 33, 00078 Monteporzio Catone, Italy
2
Dipartimento di Fisica, Università di Roma Sapienza, Città Universitaria di Roma – Sapienza, Piazzale Aldo Moro, 2, 00185 Roma, Italy
3
NSF’s National Optical-Infrared Astronomy Research Laboratory, 950 N. Cherry Ave., Tucson, AZ 85719, USA
4
Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
5
Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, via Gobetti 93/3, I-40129 Bologna, Italy
6
INAF – Osservatorio astronomico di Padova, Vicolo Osservatorio 5, 35122 Padova, Italy
7
Dipartimento di Fisica e Astronomia ‘Galileo Galilei’, Università degli studi di Padova, Vicolo dell’Osservatorio, 3, I-35122 Padova, Italy
8
Dipartimento di Fisica, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 1, 00133 Roma, Italy
9
IPAC, California Institute of Technology, MC 314-6, 1200 E. California Boulevard, Pasadena, CA 91125, USA
10
National Astronomical Research Institute of Thailand (NARIT), Mae Rim, Chiang Mai 50180, Thailand
11
Department of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, Switzerland
12
Department of Physics and Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095, USA
13
Dipartimento di Fisica e Scienze della Terra, Universit‘a degli Studi di Ferrara, Via Saragat 1, I-44122 Ferrara, Italy
14
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
15
National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, Japan
16
School of Astronomy and Space Science, University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
17
National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China
18
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing 102206, China
19
Department of Space, Earth, & Environment, Chalmers University of Technology, Chalmersplatsen 4, 412 96 Gothenburg, Sweden
⋆ Corresponding author; lorenzo.napolitano@inaf.it
Received:
2
September
2024
Accepted:
18
November
2024
We present the JWST/NIRSpec PRISM follow-up of candidate galaxies at z ≃ 9–11 selected from deep JWST/NIRCam photometry in GLASS-JWST Early Release Science data. We spectroscopically confirm six sources with secure redshifts at z = 9.52–10.43, each showing multiple emission lines. An additional object is likely at z ≃ 10.66, based on its Lyα-break and a single emission feature, while one source is a lower-redshift interloper. The sample includes the first JWST-detected candidate at z ∼ 10, GHZ1/GLASS-z10, which we confirm at z = 9.875, and the X-ray detected active galactic nucleus (AGN) GHZ9 at z = 10.145. Three objects, including GHZ9, have EW(C III]λ1908) > 20 Å and occupy a region compatible with AGN emission in the EW(CIII]) vs CIV/CIII] diagram. The spectroscopic sample confirms a high abundance of galaxies at z > 9. We measure a number density of z ∼ 10 galaxies in the GLASS-JWST ERS field that is a factor of > 3 higher than other JWST-based estimates at demagnified rest-frame magnitudes of −21 ≤ MUV ≤ −19. We find that the positions of these galaxies in redshift and angular space are not consistent with all of them being part of a single progenitor of present-day galaxy clusters. The high density of objects in the GLASS region can be explained either by clustering on large scales or by a superposition of different forming structures of which we observe only the brightest members. By considering all the spectroscopic z ∼ 10 sources in the Abell-2744 field, we identify two potential galaxy proto-clusters centered around GHZ9 and JD1, with relative separations between their members of ≃1–2 pMpc. The potential AGN nature of three of the sources in our sample lends support to a scenario in which the high abundance of bright sources determined by JWST surveys at cosmic dawn may be affected by AGN contribution to their UV luminosity.
Key words: galaxies: active / galaxies: high-redshift / dark ages / reionization / first stars
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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