Early Results from GLASS-JWST. XIX. A High Density of Bright Galaxies at z ≈ 10 in the A2744 Region

Year: 2023

Type: article

Abstract: We report the detection of a high density of redshift z ≈ 10 galaxies behind the foreground cluster A2744, selected from imaging data obtained recently with NIRCam on board JWST by three programs—GLASS-JWST, UNCOVER, and DDT#2756. To ensure robust estimates of the lensing magnification μ, we use an improved version of our model that exploits the first epoch of NIRCam images and newly obtained MUSE spectra and avoids regions with μ > 5 where the uncertainty may be higher. We detect seven bright z ≈ 10 galaxies with demagnified rest frame −22 ≲ M UV ≲ −19 mag, over an area of ∼37 arcmin2. Taking into account photometric incompleteness and the effects of lensing on luminosity and cosmological volume, we find that the density of z ≈ 10 galaxies in the field is about 10× (3×) larger than the average at M UV ≈ −21 ( −20) mag reported so far. The density is even higher when considering only the GLASS-JWST data, which are the deepest and the least affected by magnification and incompleteness. The GLASS-JWST field contains five out of seven galaxies, distributed along an apparent filamentary structure of 2 Mpc in projected length, and includes a close pair of candidates with M UV < −20 mag having a projected separation of only 16 kpc. These findings suggest the presence of a z ≈ 10 overdensity in the field. In addition to providing excellent targets for efficient spectroscopic follow-up observations, our study confirms the high density of bright galaxies observed in early JWST observations but calls for multiple surveys along independent lines of sight to achieve an unbiased estimate of their average density and a first estimate of their clustering.

Source: The Astrophysical Journal Letters

DOI: 10.3847/2041-8213/accea5

Institutions: Astronomical Observatory of Rome, National Institute for Astrophysics, University of California, Los Angeles, University of Milan, Osservatorio di Astrofisica e Scienza dello Spazio, University of Ferrara, National Astronomical Research Institute of Thailand, Agenzia Spaziale Italiana, Trieste Astronomical Observatory, The University of Melbourne, ASTRO-3D, ARC Centre of Excellence for All-sky Astrophysics, University of Copenhagen, Ikerbasque, University of the Basque Country, Donostia International Physics Center, Max Planck Institute for Astrophysics, Technical University of Munich, University of Minnesota, University of California, Berkeley, Swinburne University of Technology, Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, University of Salerno, Astronomical Observatory of Capodimonte, California Institute of Technology, Infrared Processing and Analysis Center, Johns Hopkins University, Osservatorio Astronomico di Padova, Kavli Institute for the Physics and Mathematics of the Universe, The University of Tokyo, Chinese Academy of Sciences, Beijing Normal University, National Astronomical Observatories, University of Chinese Academy of Sciences

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,400

Funders: National Aeronautics and Space Administration, Villum Fonden, Space Telescope Science Institute, National Research Foundation, Danmarks Grundforskningsfond, Ministero dell’Istruzione, dell’Università e della Ricerca, Japan Society for the Promotion of Science

Awards: G103270039, G112473895, G1338664626, G1378887243, G253494089, G256731684, Distribution of distant galaxy size and luminosity, Cosmic Dawn Center (DAWN), G4375798180, G4863782507, G5239345138, G5568641063, G6462785651, Zooming into Dark Matter and proto-galaxies with massive lensing clusters, G785121043

OpenAlex ID: W4377016713