A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327
The first science image released by the James Webb Space Telescope (JWST) reveals numerous galaxies in the distant background of the galaxy cluster SMACS J0723.3-7327. Some have claimed redshifts of up to z ≃ 20, challenging standard cosmological models for structure formation. Here, we present a le...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ad1246 |
| _version_ | 1797333433767165952 |
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| author | Alex Chow Sung Kei Li Jeremy Lim Tom Broadhurst Man Cheung Alex Li James Nianias Jake Summers Rogier Windhorst |
| author_facet | Alex Chow Sung Kei Li Jeremy Lim Tom Broadhurst Man Cheung Alex Li James Nianias Jake Summers Rogier Windhorst |
| author_sort | Alex Chow |
| collection | DOAJ |
| description | The first science image released by the James Webb Space Telescope (JWST) reveals numerous galaxies in the distant background of the galaxy cluster SMACS J0723.3-7327. Some have claimed redshifts of up to z ≃ 20, challenging standard cosmological models for structure formation. Here, we present a lens model for SMACS J0723.3-7327 anchored on five spectroscopically confirmed systems at 1.38 ≤ z ≤ 2.21 that are multiply lensed, along with 12 other systems with proposed image counterparts sharing common colors, spectral energy distributions, and morphological features, but having unknown redshifts. Constrained only by their image positions, and where available, redshifts, our lens model correctly reproduces the positions and correctly predicts the morphologies and relative brightnesses of all these image counterparts, as well as providing geometrically determined redshifts spanning 1.4 ≲ z ≲ 6.7 for the 12 candidate multiply lensed galaxies lacking spectroscopic measurements. From this lens model, we create a lens finder map that defines regions over which galaxies beyond a certain redshift are predicted to be multiply lensed. Applying this map to three galaxies claimed to be at 10 ≲ z ≲ 20, we find no image counterparts at locations (with an uncertainty of ∼0.″5) where they ought to be sufficiently magnified to be detectable—suggesting instead that these galaxies lie at z ≲ 1.7–3.2. In lieu of spectroscopy, the creation of reliable lens finder maps for cluster fields is urgently needed to test and constrain redshifts inferred from photometry for a rapidly increasing number of candidate high- z galaxies found with JWST. |
| first_indexed | 2024-03-08T08:04:46Z |
| format | Article |
| id | doaj.art-93e9519613674e9e8b963103e1cf66d9 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T08:04:46Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-93e9519613674e9e8b963103e1cf66d92024-02-02T11:26:10ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0196213010.3847/1538-4357/ad1246A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327Alex Chow0https://orcid.org/0000-0003-3878-9118Sung Kei Li1https://orcid.org/0000-0002-4490-7304Jeremy Lim2https://orcid.org/0000-0003-4220-2404Tom Broadhurst3https://orcid.org/0000-0002-8785-8979Man Cheung Alex Li4https://orcid.org/0000-0002-0000-9895James Nianias5https://orcid.org/0000-0001-6985-2939Jake Summers6https://orcid.org/0000-0002-7265-7920Rogier Windhorst7https://orcid.org/0000-0001-8156-6281Department of Physics, The University of Hong Kong , Pokfulam Road, Hong KongDepartment of Physics, The University of Hong Kong , Pokfulam Road, Hong KongDepartment of Physics, The University of Hong Kong , Pokfulam Road, Hong KongDepartment of Theoretical Physics, University of the Basque Country UPV/EHU , Bilbao, Spain; Donostia International Physics Center (DIPC) , E-20018 Donostia, Spain; IKERBASQUE, Basque Foundation for Science , Bilbao, SpainDepartment of Physics, The University of Hong Kong , Pokfulam Road, Hong KongDepartment of Physics, The University of Hong Kong , Pokfulam Road, Hong KongSchool of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USASchool of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287-1404, USAThe first science image released by the James Webb Space Telescope (JWST) reveals numerous galaxies in the distant background of the galaxy cluster SMACS J0723.3-7327. Some have claimed redshifts of up to z ≃ 20, challenging standard cosmological models for structure formation. Here, we present a lens model for SMACS J0723.3-7327 anchored on five spectroscopically confirmed systems at 1.38 ≤ z ≤ 2.21 that are multiply lensed, along with 12 other systems with proposed image counterparts sharing common colors, spectral energy distributions, and morphological features, but having unknown redshifts. Constrained only by their image positions, and where available, redshifts, our lens model correctly reproduces the positions and correctly predicts the morphologies and relative brightnesses of all these image counterparts, as well as providing geometrically determined redshifts spanning 1.4 ≲ z ≲ 6.7 for the 12 candidate multiply lensed galaxies lacking spectroscopic measurements. From this lens model, we create a lens finder map that defines regions over which galaxies beyond a certain redshift are predicted to be multiply lensed. Applying this map to three galaxies claimed to be at 10 ≲ z ≲ 20, we find no image counterparts at locations (with an uncertainty of ∼0.″5) where they ought to be sufficiently magnified to be detectable—suggesting instead that these galaxies lie at z ≲ 1.7–3.2. In lieu of spectroscopy, the creation of reliable lens finder maps for cluster fields is urgently needed to test and constrain redshifts inferred from photometry for a rapidly increasing number of candidate high- z galaxies found with JWST.https://doi.org/10.3847/1538-4357/ad1246Strong gravitational lensingGalaxy clusters |
| spellingShingle | Alex Chow Sung Kei Li Jeremy Lim Tom Broadhurst Man Cheung Alex Li James Nianias Jake Summers Rogier Windhorst A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327 The Astrophysical Journal Strong gravitational lensing Galaxy clusters |
| title | A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327 |
| title_full | A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327 |
| title_fullStr | A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327 |
| title_full_unstemmed | A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327 |
| title_short | A Lens Finder Map to Check Claimed High-z Galaxies behind SMACS J0723.3-7327 |
| title_sort | lens finder map to check claimed high z galaxies behind smacs j0723 3 7327 |
| topic | Strong gravitational lensing Galaxy clusters |
| url | https://doi.org/10.3847/1538-4357/ad1246 |
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