{
  "id": "2102.10706",
  "version": "v1",
  "published": "2021-02-21T22:40:53.000Z",
  "updated": "2021-02-21T22:40:53.000Z",
  "title": "The ALMA Spectroscopic Survey in the HUDF: A Search for [CII] Emitters at $6 \\leq z \\leq 8$",
  "authors": [
    "Bade D. Uzgil",
    "Pascal A. Oesch",
    "Fabian Walter",
    "Manuel Aravena",
    "Leindert Boogaard",
    "Chris Carilli",
    "Roberto Decarli",
    "Tanio Díaz-Santos",
    "Yoshi Fudamoto",
    "Hanae Inami",
    "Rychard Bouwens",
    "Paulo C. Cortes",
    "Pierre Cox",
    "Emmanuele Daddi",
    "Jorge González-López",
    "Ivo Labbe",
    "Gergö Popping",
    "Dominik Riechers",
    "Mauro Stefanon",
    "Paul Van der Werf",
    "Axel Weiss"
  ],
  "comment": "16 pages, 6 figures, accepted for publication in ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "The ALMA Spectroscopic Survey in the Hubble Ultra Deep Field (ASPECS) Band 6 scan (212-272 GHz) covers potential [CII] emission in galaxies at $6\\leq z \\leq8$ throughout a 2.9 arcmin$^2$ area. By selecting on known Lyman-$\\alpha$ emitters (LAEs) and photometric dropout galaxies in the field, we perform targeted searches down to a 5$\\sigma$ [CII] luminosity depth $L_{\\mathrm{[CII]}}\\sim2.0\\times10^8$ L$_{\\odot}$, corresponding roughly to star formation rates (SFRs) of $10$-$20$ M$_{\\odot}$ yr$^{-1}$ when applying a locally calibrated conversion for star-forming galaxies, yielding zero detections. While the majority of galaxies in this sample are characterized by lower SFRs, the resulting upper limits on [CII] luminosity in these sources are consistent with the current literature sample of targeted ALMA observations of $z=6$-$7$ LAEs and Lyman-break galaxies (LBGs), as well as the locally calibrated relations between $L_{\\mathrm{[CII]}}$ and SFR -- with the exception of a single [CII]-deficient, UV luminous LBG. We also perform a blind search for [CII]-bright galaxies that may have been missed by optical selections, resulting in an upper limit on the cumulative number density of [CII] sources with $L_{\\mathrm{[CII]}}>2.0\\times10^8$ L$_{\\odot}$ ($5\\sigma $) to be less than $1.8\\times10^{-4}$ Mpc$^{-3}$ (90% confidence level). At this luminosity depth and volume coverage, we present an observed evolution of the [CII] luminosity function from $z=6$-$8$ to $z\\sim0$ by comparing the ASPECS measurement to literature results at lower redshift.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-02-21T22:40:53.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "alma spectroscopic survey",
      "upper limit",
      "luminosity depth",
      "hubble ultra deep field",
      "star formation rates"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 16,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}