{
  "id": "1806.07732",
  "version": "v1",
  "published": "2018-06-20T13:51:17.000Z",
  "updated": "2018-06-20T13:51:17.000Z",
  "title": "Nature and chemical abundances of a sample of Lyman-$α$ emitter objects at high redshift",
  "authors": [
    "O. L. Dors",
    "B. Agarwal",
    "G. F. Hagele",
    "M. V. Cardaci",
    "C. -E. Rydberg",
    "R. A. Riffel",
    "A. S. Oliveira",
    "A. C. Krabbe"
  ],
  "comment": "32 pages, MNRAS accepted",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We built a grid of photoionization models and compiled already available observational emission line intensities ($\\rm 1000 \\: < \\: \\lambda(\\AA) \\: < \\: 2000$) of confirmed star formation regions and Active Galactic Nucleus (AGNs) in order to classify five Ly$\\alpha$ emitter (LAE) objects at high redshift $(5.7 \\: < \\: z \\: < \\:7.2)$. We selected objects for which at least one metal emission-line was measured. The resulting sample is composed by the objects RXCJ2248.7-4431-ID3, HSCJ233408+004403, COSY, A1703-zd6, and CR7 (clump C). The photoionization models were built assuming a Power Law (associated with the presence of an AGN), a Direct Collapse Black Hole (DCBH), and Population II stars for the ionizing source. The resulting models were then compared with observational emission-line ratios in six diagnostic diagrams to produce a spectral classification of the sample. We found that CR7 (clump C), HSCJ233408+004403 and COSY probably have a non thermal ionizing source (AGN or DCBH) while the RXC J2248.7-4431-ID3 and A1703-zd6 seem to host a stellar cluster. Detailed photoionization models were constructed to reproduce observational emission line ratios of the sample of LAEs, and to derive chemical abundances and number of ionizing photons $Q(\\rm H)$ of these objects. From these models, we found metallicities in the range $(Z/Z_{\\odot})=0.1-0.5$ and $\\log Q(\\rm H) \\: > \\: 53$. Values for C/O abundance ratio derived for the LAEs seem to be consistent with those derived for local star forming objects with similar metallicities, while an overabundance of N/O was found for most of the LAEs.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-06-20T13:51:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high redshift",
      "chemical abundances",
      "emitter objects",
      "photoionization models",
      "reproduce observational emission line ratios"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 32,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}