Galaxy counts on the cosmic microwave background cold spot

Benjamin R. Granett, Istvn Szapudi, Mark C. Neyrinck

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29 Citations (Scopus)


The cold spot on the cosmic microwave background (CMB) could arise due to a supervoid at low redshift through the integrated Sachs-Wolfe effect. We imaged the region with MegaCam on the Canada-France-Hawaii Telescope and present galaxy counts in photometric redshift bins. We rule out the existence of a 100 Mpc radius spherical supervoid with underdensity δ = -0.3 at 0.5 < z < 0.9 at high significance. The data are consistent with an underdensity at low redshift, but the fluctuations are within the range of cosmic variance and the low-density areas are not contiguous on the sky. Thus, we find no strong evidence for a supervoid. We cannot resolve voids smaller than a 50 Mpc radius; however, these can only make a minor contribution to the CMB temperature decrement.

Original languageEnglish
Pages (from-to)825-833
Number of pages9
JournalAstrophysical Journal
Issue number1
Publication statusPublished - Jan 1 2010



  • Cosmic background radiation
  • Cosmology: observations
  • Large-scale structure of universe
  • Methods: statistical

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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