Evolution of Nonparametric Morphology of Galaxies in the JWST CEERS Field at z ≃ 0.8–3.0

Abstract

Galaxy morphology is one of the most fundamental ways to describe galaxy properties, but the morphology we observe may be affected by wavelength and spatial resolution, which may introduce systematic bias when comparing galaxies at different redshift. Taking advantage of the broad wavelength coverage from optical to near-IR and the high-resolution NIRCam instrument of the JWST, we measure the nonparametric morphological parameters of a total of 1376 galaxies at z ≃ 0.8–3.0 in the CEERS field through an optimized code called statmorph_csst. We divide our sample into three redshift intervals and investigate the wavelength and redshift dependence of the morphological parameters. We also explore how the widely used galaxy type classification methods based on the morphological parameters depend on wavelength and spatial resolution. We find that there are variations in all morphological parameters with rest-frame wavelength (λ rf), especially at the short-wavelength end, and that λ rf mainly affects the classification between late- and early-type galaxies. As λ rf increases, the galaxies on the G–M 20 diagram move to the upper left with a slope of −0.23 ± 0.03 on average. We find that spatial resolution mainly affects the merger identification. The merger fraction in F200W resolution can be ≳2 times larger than that in F444W resolution. Furthermore, we compare the morphological parameter evolution of galaxies with different stellar masses. We find that there are differences in the morphological evolution of high- and low-mass (log M * ≥ 10 and 9 < log M * < 10) galaxies in the studied redshift range, which may be caused by their different evolutionary paths.

Rest-frame Near-infrared Radial Light Profiles up to z = 3 from JWST/NIRCam: Wavelength Dependence of the Sérsic Index

“…As stellar populations and dust attenuation determine the light distribution, the measured structural properties are generally observed to depend on the wavelength (e.g., de Jong 1996ade Jong , 1996bKelvin et al 2012;Häußler et al 2013;Pastrav et al 2013;Vika et al 2013;Vulcani et al 2014;Kennedy et al 2015;Baes et al 2020;Nersesian et al 2023;Yao et al 2023). Kelvin et al (2012) used the low-redshift (z < 0.3) Galaxy And Mass Assembly (GAMA) survey (Driver et al 2009) to examine the dependence of the Sérsic index on the wavelength, splitting the galaxy sample by visual morphology (disk galaxies and spheroidal galaxies).…”

Evidence for an intermediate mass black hole in a low-mass star-forming galaxy

“…MaNGA 9885-9102 is originally selected from the investigation of non-parametric morphology [52] of emission line flux map from the Data Analysis Pipeline (DAP) of MaNGA [53,54] galaxies [55,56]. We conduct a manual visual inspection of the galaxies with special features.…”

USmorph: An Updated Framework of Automatic Classification of Galaxy Morphologies and Its Application to Galaxies in the COSMOS Field

“…For example, it is commonly accepted that elliptical galaxies tend to have a Sérsic index greater than 2, while disk galaxies typically exhibit a Sérsic index less than 2 (e.g., Fisher & Drory 2008;Blanton & Moustakas 2009). Nonparametric structural parameters also offer valuable insights into galaxy morphological types, as different galaxy categories often occupy distinct positions in parameter space (e.g., Lotz et al 2008;Yao et al 2023).…”

“…Rodriguez-Gomez et al (2019) developed a python package statmorph for calculating the nonparametric morphologies of galaxies, including Gini, M 20 , C, A, S, M, I, and D. Based on this package, Yao et al (2023) optimized the code with Cython (Behnel et al 2011) and increased the calculation speed by 1 order of magnitude, which is suitable for large-scale surveys. In addition, Yao et al (2023) also incorporated some additional optional parameters into statmorph, including the color dispersion (ξ; Papovich et al 2003), multiplicity (Ψ;Law et al 2007), and the second gradient moment (G 2 ; Rosa et al 2018). The improved code has been named stat-morph_csst.…”