{
  "id": "1512.01253",
  "version": "v1",
  "published": "2015-12-03T21:21:35.000Z",
  "updated": "2015-12-03T21:21:35.000Z",
  "title": "How does our choice of observable influence our estimation of the centre of a galaxy cluster? Insights from cosmological simulations",
  "authors": [
    "Weiguang Cui",
    "Chris Power",
    "Veronica Biffi",
    "Stefano Borgani",
    "Alexander Knebe",
    "Giuseppe Murante",
    "Dunja Fabjan",
    "Geraint F. Lewis",
    "Greg B. Poole"
  ],
  "comment": "11 pages, 6 figures, MNRAS accepted",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Galaxy clusters are an established and powerful test-bed for theories of both galaxy evolution and cosmology. Accurate interpretation of cluster observations often requires robust identification of the location of the centre. Using a statistical sample of clusters drawn from a suite of cosmological simulations in which we have explored a range of galaxy formation models, we investigate how the location of this centre is affected by the choice of observable - stars, hot gas, or the full mass distribution as can be probed by the gravitational potential. We explore several measures of cluster centre: the minimum of the gravitational potential, which would expect to define the centre if the cluster is in dynamical equilibrium; the peak of the density; the centre of BCG; and the peak and centroid of X-ray luminosity. We find that the centre of BCG correlates more strongly with the minimum of the gravitational potential than the X-ray defined centres, while AGN feedback acts to significantly enhance the offset between the peak X-ray luminosity and minimum gravitational potential. These results highlight the importance of centre identification when interpreting clusters observations, in particular when comparing theoretical predictions and observational data.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-12-03T21:21:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galaxy cluster",
      "cosmological simulations",
      "observable influence",
      "estimation",
      "galaxy formation models"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}