Abstract
We present a rest-frame optical morphological analysis of galaxies observed with the NIRCam imager on the James Webb Space Telescope (JWST) as part of the GLASS-JWST Early Release Science program. We select 388 sources at redshifts 0.8 < z < 5.4 and use the seven 0.9-5 mu m NIRCam filters to generate rest-frame gri composite color images, and conduct visual morphological classification. Compared to Hubble Space Telescope (HST)-based work we find a higher incidence of disks and bulges than expected at z > 1.5, revealed by rest-frame optical imaging. We detect 123 clear disks (58 at z > 1.5) of which 76 have bulges. No evolution of bulge fraction with redshift is evident: 61% at z < 2 (N = 110) versus 60% at z >= 2 (N = 13). A stellar mass dependence is evident, with bulges visible in 80% of all disk galaxies with mass >10(9.5) M (circle dot) (N = 41) but only 52% at M < 10(9.5) M (circle dot) (N = 82). We supplement visual morphologies with nonparametric measurements of Gini and asymmetry coefficients in the rest-frame i band. Our sources are more asymmetric than local galaxies, with slightly higher Gini values. When compared to high-z rest-frame ultraviolet measurements with HST, JWST shows more regular morphological types such as disks, bulges, and spiral arms at z > 1.5, with smoother (i.e., lower Gini) and more symmetrical light distributions.
Original language | English |
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Article number | 13 |
Journal | Astrophysical Journal Letters |
Volume | 948 |
Issue number | 2 |
Number of pages | 9 |
ISSN | 2041-8205 |
DOIs | |
Publication status | Published - 1 May 2023 |
Keywords
- DIGITAL SKY SURVEY
- STAR-FORMATION ACTIVITY
- EARLY-TYPE GALAXIES
- SIMILAR-TO 2
- MASSIVE GALAXIES
- DISTANT GALAXIES
- HUBBLE SEQUENCE
- SURVEY DESIGN
- DATA RELEASE
- DEEP FIELD