{
  "id": "2208.00612",
  "version": "v1",
  "published": "2022-08-01T05:18:36.000Z",
  "updated": "2022-08-01T05:18:36.000Z",
  "title": "Newly discovered $z\\sim5$ quasars based on deep learning and Bayesian information criterion",
  "authors": [
    "Suhyun Shin",
    "Myungshin Im",
    "Yongjung Kim",
    "Linhua Jiang"
  ],
  "comment": "8 pages, 5 figures, Accepted for publication in JKAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We report the discovery of four quasars with $M_{1450} \\gtrsim -25.0$ mag at $z\\sim5$ and supermassive black hole mass measurement for one of the quasars. They were selected as promising high-redshift quasar candidates via deep learning and Bayesian information criterion, which are expected to be effective in discriminating quasars from the late-type stars and high-redshift galaxies. The candidates were observed by the Double Spectrograph on the Palomar 200-inch Hale Telescope. They show clear Ly$\\alpha$ breaks at about 7000-8000 \\r{A}, indicating they are quasars at $4.7 < z < 5.6$. For HSC J233107-001014, we measure the mass of its supermassive black hole (SMBH) using its C\\Romannum{4}$\\lambda 1549$ emission line. The SMBH mass and Eddington ratio of the quasar are found to be $\\sim 10^8 M_{\\odot}$ and $\\sim 0.6$, respectively. This suggests that this quasar possibly harbors a fast growing SMBH near the Eddington limit despite its faintness ($L_{\\rm Bol} < 10^{46}$ erg s$^{-1}$). Our 100 $\\%$ quasar identification rate supports high efficiency of our deep learning and Bayesian information criterion selection method, which can be applied to future surveys to increase high-redshift quasar sample.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-08-01T05:18:36.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "deep learning",
      "black hole mass measurement",
      "rate supports high efficiency",
      "quasar identification rate supports high",
      "bayesian information criterion selection method"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}