2014/07/06 by Kovács, András, Szapudi, István, Granett, Benjamin R. +13 · 1 citation
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences
paper · doi:10.48550/arxiv.1407.1470
We use a WISE-2MASS-Pan-STARRS1 galaxy catalog to search for a supervoid in the direction of the Cosmic Microwave Background Cold Spot. We obtain photometric redshifts using our multicolor data set to create a tomographic map of the galaxy distribution. The radial density profile centred on the Cold Spot shows a large low density region, extending over 10's of degrees. Motivated by previous Cosmic Microwave Background results, we test for underdensities within two angular radii, 5^∘, and 15^∘. Our data, combined with an earlier measurement by Granett et al 2010, are consistent with a large R\rm void=(192 ± 15)h-1 Mpc (2σ) supervoid with δ≃ -0.13 ± 0.03 centered at z=0.22±0.01. Such a supervoid, constituting a ∼3.5 σ fluctuation in the ΛCDM model, is a plausible cause for the Cold Spot.