JWST Insight into a Lensed HST-dark Galaxy and Its Quiescent Companion at z=2.58
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- Kokorev_2023_ApJL_945_L25
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Using the novel James Webb Space Telescope (JWST)/NIRCam observations in the A2744 field, we present a first spatially resolved overview of a Hubble Space Telescope (HST)-dark galaxy, spectroscopically confirmed at z = 2.58 with magnification mu approximate to 1.9. While being largely invisible at similar to 1 mu m with NIRCam, except for sparse clumpy substructures, the object is well detected and resolved in the long-wavelength bands with a spiral shape clearly visible in F277W. By combining ancillary Atacama Large Millimeter/submillimeter Array (ALMA) and Herschel data, we infer that this object is an edge-on dusty spiral with an intrinsic stellar mass log (M (*)/M (circle dot)) similar to 11.3 and a dust-obscured star formation rate similar to 300 M (circle dot) yr(-1). A massive quiescent galaxy (log (M (*)/M (circle dot)) similar to 10.8) with tidal features lies 2.'' 0 away (r similar to 9 kpc), at a consistent redshift as inferred by JWST photometry, indicating a potential major merger. The dusty spiral lies on the main sequence of star formation, and shows high dust attenuation in the optical (3 < A ( V ) < 4.5). In the far-infrared, its integrated dust spectral energy distribution is optically thick up to lambda (0) similar to 500 mu m, further supporting the extremely dusty nature. Spatially resolved analysis of the HST-dark galaxy reveals a largely uniform A ( V ) similar to 4 area spanning similar to 57 kpc(2), which spatially matches to the ALMA 1 mm continuum emission. Accounting for the surface brightness dimming and the depths of current JWST surveys, unlensed analogs of the HST-dark galaxy at z > 4 would be only detectable in F356W and F444W in an UNCOVER-like survey, and become totally JWST-dark at z similar to 6. This suggests that detecting highly attenuated galaxies in the Epoch of Reionization might be a challenging task for JWST.
Original language | English |
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Article number | 25 |
Journal | Astrophysical Journal Letters |
Volume | 945 |
Issue number | 2 |
Number of pages | 11 |
ISSN | 2041-8205 |
DOIs | |
Publication status | Published - 1 Mar 2023 |
- STAR-FORMING GALAXIES, EVOLVING INTERSTELLAR-MEDIUM, COSMOLOGY LEGACY SURVEY, LENSING CLUSTER SURVEY, DEEP-FIELD-SOUTH, EXTREMELY RED H, MASSIVE GALAXIES, SUBMILLIMETER GALAXIES, BILLION YEARS, ALMA SURVEY
Research areas
ID: 342498499