{
  "id": "1810.13142",
  "version": "v1",
  "published": "2018-10-31T07:59:56.000Z",
  "updated": "2018-10-31T07:59:56.000Z",
  "title": "Interplanetary Scintillation studies with the Murchison Wide-field Array IV: The hosts of sub-arcsecond compact sources at low radio frequencies",
  "authors": [
    "Elaine M. Sadler",
    "Rajan Chhetri",
    "John Morgan",
    "Elizabeth K. Mahony",
    "Thomas H. Jarrett",
    "Steven Tingay"
  ],
  "comment": "21 pages, 6 figures, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Around 10% of bright low-frequency radio sources observed with the Murchison Widefield Array (MWA) show strong Interplanetary Scintillation (IPS) on timescales of a few seconds, implying that almost all their low-frequency radio emission comes from a compact component less than 0.5 arcsec in angular size. Most of these objects are compact steep-spectrum (CSS) or MHz-peaked spectrum (MPS) radio sources. We have used mid-infrared data from the Wide-field Infrared Survey Explorer (WISE) catalogue to search for the host galaxies of 65 strongly-scintillating MWA sources and compare their properties with those of the overall population of bright low-frequency radio sources. We identified WISE mid-infrared counterparts for 91% of the bright sources in a single 900 square degree MWA field, and found that the hosts of the strongly-scintillating sources were typically at least 1 mag fainter in the WISE W1 (3.4 micron) band than the hosts of weakly-scintillating MWA sources of similar radio flux density. This difference arises mainly because the strongly-scintillating sources are more distant. We estimate that strongly-scintillating MWA sources have a median redshift of z ~ 1.5, and that at least 30% of them are likely to lie at z > 2. The recently-developed wide-field IPS technique therefore has the potential to provide a powerful new tool for identifying high-redshift radio galaxies without the need for radio spectral-index selection.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-10-31T07:59:56.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "low radio frequencies",
      "interplanetary scintillation studies",
      "murchison wide-field array",
      "sub-arcsecond compact sources",
      "bright low-frequency radio sources"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 21,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}