{
  "id": "2304.06090",
  "version": "v1",
  "published": "2023-04-12T18:12:38.000Z",
  "updated": "2023-04-12T18:12:38.000Z",
  "title": "Morphological asymmetries of quasar host galaxies with Subaru Hyper Suprime-Cam",
  "authors": [
    "Shenli Tang",
    "John D. Silverman",
    "Hassen M. Yesuf",
    "Xuheng Ding",
    "Junyao Li",
    "Connor Bottrell",
    "Andy Goulding",
    "Kiyoaki Christopher Omori",
    "Yoshiki Toba",
    "Toshihiro Kawaguchi"
  ],
  "comment": "27 pages, 28 figures",
  "journal": "MNRAS, volume 521, number 4, pages 5272--5297 (2023)",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "How does the host galaxy morphology influence a central quasar or vice versa? We address this question by measuring the asymmetries of 2424 SDSS quasar hosts at $0.2<z<0.8$ using broad-band ($grizy$) images from the Hyper Suprime-Cam Subaru Strategic Program. Control galaxies (without quasars) are selected by matching the redshifts and stellar masses of the quasar hosts. A two-step pipeline is run to decompose the PSF and \\sersic\\ components, and then measure asymmetry indices ($A_{\\rm CAS}$, $A_{\\rm outer}$, and $A_{\\rm shape}$) of each quasar host and control galaxy. We find a mild correlation between host asymmetry and AGN bolometric luminosity ($L_{\\rm bol}$) for the full sample (spearman correlation of 0.37) while a stronger trend is evident at the highest luminosities ($L_{\\rm bol}>45$). This then manifests itself into quasar hosts being more asymmetric, on average, when they harbor a more massive and highly accreting black hole. The merger fraction also positively correlates with $L_{\\rm bol}$ and reaches up to 35\\% for the most luminous. Compared to control galaxies, quasar hosts are marginally more asymmetric (excess of 0.017 in median at 9.4$\\sigma$ level) and the merger fractions are similar ($\\sim 16.5\\%$). We quantify the dependence of asymmetry on optical band which demonstrates that mergers are more likely to be identified with the bluer bands and the correlation between $L_{\\rm bol}$ and asymmetry is also stronger in such bands. We stress that the band dependence, indicative of a changing stellar population, is an important factor in considering the influence of mergers on AGN activity.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-04-12T18:12:38.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quasar host galaxies",
      "subaru hyper suprime-cam",
      "morphological asymmetries",
      "control galaxy",
      "hyper suprime-cam subaru strategic program"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 27,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}