{
  "id": "astro-ph/0304407",
  "version": "v1",
  "published": "2003-04-23T07:14:14.000Z",
  "updated": "2003-04-23T07:14:14.000Z",
  "title": "The origin of X-ray emission of two distant (z>1) cluster candidate with XMM-Newton",
  "authors": [
    "D. M. Neumann",
    "M. Arnaud",
    "C. Benoist",
    "L. da Costa",
    "H. E. Jørgensen",
    "L. F. Olsen",
    "S. Bardelli",
    "E. Zucca",
    "S. Arnouts",
    "A. Biviano",
    "M. Ramella"
  ],
  "comment": "Accepted for publication in A&A, 8 pages, 4 figures, figure 1 submitted as jpeg file",
  "journal": "Astron.Astrophys. 406 (2003) 789-796",
  "doi": "10.1051/0004-6361:20030657",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We present here a study of XMM-Newton data of two distant galaxy cluster candidates. One of these was discovered serendipitously in near infrared data, CL J0533-2411, the other one corresponds to the cluster EIS J0533-2412 part of the EIS cluster survey. The estimated redshift of CL J0533-2411 is z=1.2-1.7. EIS J0533-2412 is a rich system (Lambda_cl=299), with a spectroscopically confirmed redshift of z=1.3. Both galaxy concentrations show firm X-ray detections, located within 30\" of their optical center. However, we cannot resolve the sources with XMM-Newton. If the X-ray emission originates from the X-ray emitting intra-cluster medium (ICM) it would be extremely concentrated which is rather unlikely (core radii below 14 h_{65}^{-1}kpc and 40 h_{65}^{-1}kpc, respectively). We argue that the X-ray sources are more likely AGN members of the galaxy concentrations. We set an upper limit for the bolometric luminosity of a hot ICM in the range ~0.7-2.1 10^{44} h_{65}^{-2}erg/s for CL J0533-2411, depending on the exact redshift. For EIS J0533-2412 the limit is L_bol=(6.2+/-1.4) 10^{43} h_{65}^{-2}erg/s. We interpret our result in the following way: EIS J0533-2412 (and possibly CL J0533-2411) are proto-clusters and show matter overdensities before collapse, which explains the low significance of extended X-ray emission.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2003-04-23T07:14:14.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "xmm-newton",
      "galaxy concentrations",
      "distant galaxy cluster candidates",
      "x-ray emission originates",
      "eis cluster survey"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 617433
    }
  }
}