{
  "id": "2101.07827",
  "version": "v1",
  "published": "2021-01-19T19:18:20.000Z",
  "updated": "2021-01-19T19:18:20.000Z",
  "title": "Source Counts Spanning Eight Decades of Flux Density at 1.4 GHz",
  "authors": [
    "A. M. Matthews",
    "J. J. Condon",
    "W. D. Cotton",
    "T. Mauch"
  ],
  "comment": "19 pages, 13 figures, accepted for publication in ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Brightness-weighted differential source counts $S^2 n(S)$ spanning the eight decades of flux density between $0.25\\,\\mu\\mathrm{Jy}$ and 25 Jy at 1.4 GHz were measured from (1) the confusion brightness distribution in the MeerKAT DEEP2 image below $10\\,\\mu\\mathrm{Jy}$, (2) counts of DEEP2 sources between $10\\,\\mu\\mathrm{Jy}$ and $2.5\\,\\mathrm{mJy}$, and (3) counts of NVSS sources stronger than $2.5\\,\\mathrm{mJy}$. We present our DEEP2 catalog of $1.7 \\times 10^4$ discrete sources complete above $S = 10\\,\\mu\\mathrm{Jy}$ over $\\Omega = 1.04\\,\\mathrm{deg}^2$. The brightness-weighted counts converge as $S^2 n(S) \\propto S^{1/2}$ below $S = 10\\,\\mu\\mathrm{Jy}$, so $>99\\%$ of the $\\Delta T_\\mathrm{b} \\sim 0.06\\,\\mathrm{K}$ sky brightness produced by active galactic nuclei and $\\approx96\\%$ of the $\\Delta T_\\mathrm{b} \\sim 0.04\\,\\mathrm{K}$ added by star-forming galaxies has been resolved into sources with $S \\geq 0.25\\,\\mu\\mathrm{Jy}$. The $\\Delta T_\\mathrm{b} \\approx 0.4\\,\\mathrm{K}$ excess brightness measured by ARCADE 2 cannot be produced by faint sources smaller than $\\approx 50\\,\\mathrm{kpc}$ if they cluster like galaxies.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-01-19T19:18:20.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "flux density",
      "source counts spanning",
      "faint sources smaller",
      "confusion brightness distribution",
      "meerkat deep2 image"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 19,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}