{
  "id": "2209.07539",
  "version": "v1",
  "published": "2022-09-15T18:00:02.000Z",
  "updated": "2022-09-15T18:00:02.000Z",
  "title": "Origin and evolution of ultra-diffuse galaxies in different environments",
  "authors": [
    "Jose A. Benavides",
    "Laura V. Sales",
    "Mario. G. Abadi",
    "Federico Marinacci",
    "Mark Vogelsberger",
    "Lars Hernquist"
  ],
  "comment": "17 pages, 13 figures, submitted to MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We study the formation of ultra-diffuse galaxies (UDGs) using the cosmological hydrodynamical simulation TNG50 of the Illustris-TNG suite. We define UDGs as dwarf galaxies in the stellar mass range $\\rm{7.5 \\leq log (M_{\\star} / M_{\\odot}) \\leq 9 }$ that are in the $5\\%$ most extended tail of the simulated mass-size relation. This results in a sample of UDGs with half-mass radii $\\rm{r_{h \\star } \\gtrsim 2 \\ kpc}$ and surface brightness between $\\rm{24.5}$ and $\\rm{28 \\ mag \\ arcsec^{-2}}$, similar to definitions of UDGs in observations. The large cosmological volume in TNG50 allows for a comparison of UDGs properties in different environments, from the field to galaxy clusters with virial mass $\\rm{M_{200} \\sim 2 \\times 10^{14} ~ M_{\\odot}}$. All UDGs in our sample have dwarf-mass haloes ($\\rm{M_{200}\\sim 10^{11} ~ M_{\\odot} }$) and show the same environmental trends as normal dwarfs: field UDGs are star-forming and blue while satellite UDGs are typically quiescent and red. The TNG50 simulation predicts UDGs that populate preferentially higher spin haloes and more massive haloes at fixed $\\rm{M_{\\star}}$ compared to non-UDG dwarfs. This applies also to most satellite UDGs, which are actually ``born\" UDGs in the field and infall into groups and clusters without significant changes to their size. We find, however, a small subset of satellite UDGs ($\\lesssim 10 \\%$) with present-day stellar size a factor $\\geq 1.5$ larger than at infall, confirming that tidal effects, particularly in the lower mass dwarfs, are also a viable formation mechanism for some of these dwarfs, although subdominant in this simulation.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-09-15T18:00:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "ultra-diffuse galaxies",
      "satellite udgs",
      "environments",
      "tng50 simulation predicts udgs",
      "populate preferentially higher spin haloes"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}