{
  "id": "1211.6405",
  "version": "v2",
  "published": "2012-11-27T20:02:31.000Z",
  "updated": "2013-01-10T20:32:17.000Z",
  "title": "Revisiting the Indication for a low opacity Universe for very high energy gamma-rays",
  "authors": [
    "Manuel Meyer",
    "Dieter Horns",
    "Martin Raue"
  ],
  "comment": "Contributed to the 8th Patras Workshop on Axions, WIMPs and WISPs, Chicago, July 18-22, 2012, added further discussion and references for cascade emission, main conclusion unchanged",
  "categories": [
    "astro-ph.HE",
    "astro-ph.CO"
  ],
  "abstract": "Very high energy (VHE, energy >~ 100 GeV) {\\gamma}-rays undergo pair production with photons of the extragalactic background light (EBL). Thus, the intrinsic {\\gamma}-ray flux of cosmological sources is attenuated and the Universe should be opaque to {\\gamma}-rays above a redshift dependent energy. Recently, an indication has been found that the Universe is more transparent than predicted by a lower-limit EBL model. Here, this indication is confronted with additional VHE {\\gamma}-ray spectra and different EBL models. Depending on the model for the opacity, the indication persist between a ~2.6 {\\sigma} and ~4.3 {\\sigma} confidence level.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2013-01-10T20:32:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "low opacity universe",
      "high energy gamma-rays",
      "redshift dependent energy",
      "lower-limit ebl model",
      "extragalactic background light"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1204426,
      "adsabs": "2012arXiv1211.6405M"
    }
  }
}