{
  "id": "2401.15971",
  "version": "v1",
  "published": "2024-01-29T09:01:36.000Z",
  "updated": "2024-01-29T09:01:36.000Z",
  "title": "The sizes of bright Lyman-break galaxies at $z\\simeq3-5$ with JWST PRIMER",
  "authors": [
    "R. G. Varadaraj",
    "R. A. A. Bowler",
    "M. J. Jarvis",
    "N. J. Adams",
    "N. Choustikov",
    "A. M. Koekemoer",
    "A. C. Carnall",
    "D. J. McLeod",
    "J. S. Dunlop",
    "C. T. Donnan",
    "N. A. Grogin"
  ],
  "comment": "15 pages, 9 figures, 3 tables. Submitted to MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We use data from the JWST Public Release IMaging for Extragalactic Research (PRIMER) survey to measure the size scaling relations of 1668 rest-frame UV-bright Lyman-break galaxies (LBGs) at $z=3-5$ with stellar masses $\\mathrm{log}_{10}(M_{\\star}/M_{\\odot}) > 9$. The sample was selected from seeing-dominated ground-based data, presenting an unbiased sampling of the morphology and size distributions of luminous sources. We fit S\\'ersic profiles to eight NIRCam bands and also measure a non-parametric half-light radius. We find that the size distributions with both measurements are well-fit by a log-normal distribution at all redshifts, consistent with disk formation models where size is governed by host dark-matter halo angular momentum. We find a size-redshift evolution of $R_{e} = 3.51(1+z)^{-0.60\\pm0.22}$ kpc, in agreement with JWST studies. When considering the typical (modal) size over $z=3-5$, we find little evolution with bright LBGs remaining compact at $R_{e}\\simeq0.7-0.9$ kpc. Simultaneously, we find evidence for a build-up of large ($R_{e} > 2$ kpc) galaxies by $z=3$. We find some evidence for a negatively sloped size-mass relation at $z=5$ when S\\'ersic profiles are used to fit the data in F200W. The intrinsic scatter in our size-mass relations increases at higher redshifts. Additionally, measurements probing the rest-UV (F200W) show larger intrinsic scatter than those probing the rest-optical (F356W). Finally, we leverage rest-UV and rest-optical photometry to show that disky galaxies are well established by $z=5$, but are beginning to undergo dissipative processes, such as mergers, by $z=3$. The agreement of our size-mass and size-luminosity relations with simulations provides tentative evidence for centrally concentrated star formation at high-redshift.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-01-29T09:01:36.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "jwst primer",
      "host dark-matter halo angular momentum",
      "intrinsic scatter",
      "rest-frame uv-bright lyman-break galaxies",
      "size-mass relation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}