{
  "id": "1802.06802",
  "version": "v1",
  "published": "2018-02-19T19:00:27.000Z",
  "updated": "2018-02-19T19:00:27.000Z",
  "title": "The Cosmic Web Around The Brightest Galaxies During The Epoch Of Reionization",
  "authors": [
    "Keven Ren",
    "Michele Trenti",
    "Simon J. Mutch"
  ],
  "comment": "12 pages, 7 figures, 1 table; accepted for publication in ApJ",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "The most luminous galaxies at high-redshift are generally considered to be hosted in massive dark-matter halos of comparable number density, hence residing at the center of overdensities/protoclusters. We assess the validity of this assumption by investigating the clustering around the brightest galaxies populating the cosmic web at redshift $z\\sim8-9$ through a combination of semi-analytic modeling and Monte Carlo simulations of mock Hubble Space Telescope WFC3 observations. The innovative aspect of our approach is the inclusion of a log-normal scatter parameter $\\Sigma$ in the galaxy luminosity versus halo mass relation, extending to high-$z$ the conditional luminosity function framework extensively used at low redshift. Our analysis shows that the larger the value of $\\Sigma$, the less likely that the brightest source in a given volume is hosted in the most massive halo, and hence the weaker the overdensity of neighbors. We derive a minimum value of $\\Sigma$ as a function of redshift by considering stochasticity in the halo assembly times, which affects galaxy ages and star formation rates in our modeling. We show that $\\Sigma_{min}(z)\\sim0.15-0.3$, with $\\Sigma_{min}$ increasing with redshift as a consequence of shorter halo assembly periods at higher redshifts. Current observations ($m_{AB}\\sim27$) of the environment of spectroscopically confirmed bright sources at $z>7.5$ do not show strong evidence of clustering and are consistent with our modeling predictions for $\\Sigma\\geq\\Sigma_{min}$. Deeper future observations reaching $m_{AB}\\sim28.2-29$ would have the opportunity to clearly quantify the clustering strength, and hence to constrain $\\Sigma$, investigating the physical processes that drive star formation in the early Universe.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-02-19T19:00:27.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "brightest galaxies",
      "cosmic web",
      "conditional luminosity function framework",
      "hubble space telescope wfc3 observations",
      "star formation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}