In:
The Astrophysical Journal Letters, American Astronomical Society, Vol. 946, No. 1 ( 2023-03-01), p. L16-
Abstract:
The new capabilities that JWST offers in the near- and mid-infrared (IR) are used to investigate in unprecedented detail the nature of optical/near-IR-faint, mid-IR-bright sources, with HST-dark galaxies among them. We gather JWST data from the CEERS survey in the Extended Groth Strip, jointly with HST data, and analyze spatially resolved optical-to-mid-IR spectral energy distributions to estimate photometric redshifts in two dimensions and stellar population properties on a pixel-by-pixel basis for red galaxies detected by NIRCam. We select 138 galaxies with F150W − F356W 〉 1.5 mag and F356W 〈 27.5 mag. The nature of these sources is threefold: (1) 71% are dusty star-forming galaxies (SFGs) at 2 〈 z 〈 6 with 9 〈 log M ⋆ / M ⊙ 〈 11 and a variety of specific SFRs ( 〈 1 to 〉 100 Gyr −1 ); (2) 18% are quiescent/dormant (i.e., subject to reignition/rejuvenation) galaxies (QGs) at 3 〈 z 〈 5, with log M ⋆ / M ⊙ ∼ 10 and poststarburst mass-weighted ages (0.5–1.0 Gyr); and (3) 11% are strong young starbursts with indications of high equivalent width emission lines (typically, [O iii ]+H β ) at 6 〈 z 〈 7 (XELG- z 6) and log M ⋆ / M ⊙ ∼ 9.5 . The sample is dominated by disk-like galaxies with remarkable compactness for XELG- z 6 (effective radii smaller than 0.4 kpc). Large attenuations in SFGs, 2 〈 A ( V ) 〈 5 mag, are found within 1.5 times the effective radius, approximately 2 kpc, while QGs present A ( V ) ∼ 0.2 mag. Our SED-fitting technique reproduces the expected dust emission luminosities of IR-bright and submillimeter galaxies. This study implies high levels of star formation activity between z ∼ 20 and z ∼ 10, where virtually 100% of our galaxies had already formed 10 8 M ⊙ , 60% had assembled 10 9 M ⊙ , and 10% up to 10 10 M ⊙ (in situ or ex situ).
Type of Medium:
Online Resource
ISSN:
2041-8205
,
2041-8213
DOI:
10.3847/2041-8213/acb3a5
Language:
Unknown
Publisher:
American Astronomical Society
Publication Date:
2023
detail.hit.zdb_id:
2207648-7
detail.hit.zdb_id:
2006858-X
