{
  "id": "1106.4558",
  "version": "v1",
  "published": "2011-06-22T20:15:29.000Z",
  "updated": "2011-06-22T20:15:29.000Z",
  "title": "A Strategy to Measure the Dark Energy Equation of State using the HII galaxy Hubble Relation & X-ray AGN Clustering: Preliminary Results",
  "authors": [
    "M. Plionis",
    "R. Terlevich",
    "S. Basilakos",
    "F. Bresolin",
    "E. Terlevich",
    "J. Melnick",
    "R. Chavez"
  ],
  "comment": "MNRAS in press, 12 colour figures",
  "categories": [
    "astro-ph.CO",
    "gr-qc"
  ],
  "abstract": "We explore the possibility of setting stringent constraints to the Dark Energy equation of state using alternative cosmic tracers like: (a) the Hubble relation using HII galaxies, which can be observed at much higher redshifts (z~3.5) than those currently traced by SNIa samples, and (b) the large-scale structure using the clustering of X-ray selected AGN,which have a redshift distribution peaking at z~1. We use extensive Monte-Carlo simulations to define the optimal strategy for the recovery of the dark-energy equation of state using the high redshift (z~2) Hubble relation, but accounting also for the effects of gravitational lensing, which for such high redshifts can significantly affect the derived cosmological constraints. Based on a \"Figure of Merit\" analysis, we provide estimates for the number of 2<z<3.5 tracers needed to reduce the cosmological solution space, presently provided by the Constitution SNIa set, by a desired factor. We find that it is much more efficient to increase the number of tracers than to reduce their individual uncertainties. Finally, we propose a framework to put constraints on the dark energy equation of state by using the joint likelihood of the X-ray AGN clustering and of the Hubble relation cosmological analyses. A preliminary joint analysis using the X-ray AGN clustering of the 2XMM survey and the Hubble relation of the Constitution SNIa set provide: Omega_m= 0.31+-0.01 and w=-1.06+-0.05. We also find that the joint SNIa-2XMM analysis provides significantly more stringent cosmological constraints, increasing the Figure of Merit by a factor ~2, with respect to that of the joint SNIa-BAO analysis.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-06-22T20:15:29.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dark energy equation",
      "x-ray agn clustering",
      "hii galaxy hubble relation",
      "preliminary results",
      "constitution snia set"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1111/j.1365-2966.2011.19247.x",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2011,
      "month": "Oct",
      "volume": 416,
      "number": 4,
      "pages": 2981
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 915019,
      "adsabs": "2011MNRAS.416.2981P"
    }
  }
}