Early results from GLASS-JWST XIV: A first morphological atlas of the 1 < z < 5 Universe in the rest-frame optical

• Published in: arXiv.org 2023-04
• Main Authors: Jacobs, Colin, Glazebrook, Karl, Calabrò, Antonello, Treu, Tommaso, Nanayakkara, Themiya, Jones, Tucker, Merlin, Emiliano, Abraham, Roberto G, Stevens, Adam R H, Vulcani, Benedetta, Yang, Lilan, Bonchi, Andrea, Bradac, Marusa, Castellano, Marco, Fontana, Adriano, Malkan, Matthew A, Mason, Charlotte A, Morishita, Takahiro, Paris, Diego, Trenti, Michele, Marchesini, Danilo, Wang, Xin, Santini, Paola
• Format: Article
• Language: English
• Subjects: Astronomical models; Asymmetry; Color imagery; Disk galaxies; Galactic bulge; Galactic evolution; Galactic structure; Hubble Space Telescope; Image classification; James Webb Space Telescope; Morphology; Red shift; Space telescopes
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2208.06516

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\micron\ NIRCam filters to generate rest-frame \(gri\) composite color images, and conduct visual morphological classification. Compared to 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 \(z 10^{9.5}\, {\rm M}_{\odot}\) (\(N=41\)) but only 52\% at \(M < 10^{9.5}\, {\rm M}_{\odot}\) (\(N=82\)). We supplement visual morphologies with non-parametric 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 Hubble Space Telescope, 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.