Journal article
Extragalactic radio sources and the WMAP cold spot
The Astrophysical journal, Vol.671(1), pp.40-44
12/10/2007
DOI: 10.1086/522222
Abstract
We detect a dip of 20%-45% in the surface brightness and number counts of NRAO VLA Sky Survey (NVSS) sources smoothed to a few degrees at the location of the WMAP cold spot. The dip has structure on scales of similar to 1 degrees to 10 degrees. Together with independent all-sky wavelet analyses, our results suggest that the dip in extragalactic brightness and number counts and the WMAP cold spot are physically related, i.e., that the coincidence is neither a statistical anomaly nor a WMAP foreground-correction problem. If the cold spot does originate from structures at modest redshifts, as we suggest, then there is no remaining need for non-Gaussian processes at the last scattering surface of the cosmic microwave background (CMB) to explain the cold spot. The late integrated Sachs-Wolfe effect, already seen statistically for NVSS source counts, can now be seen to operate on a single region. To create the magnitude and angular size of the WMAP cold spot requires a similar to 140 Mpc radius completely empty void at z <= 1 along this line of sight. This is far outside the current expectations of the concordance cosmology, and adds to the anomalies seen in the CMB.
Details
- Title: Subtitle
- Extragalactic radio sources and the WMAP cold spot
- Creators
- Lawrence Rudnick - University of MinnesotaShea Brown - University of MinnesotaLiliya R. Williams - University of Minnesota
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.671(1), pp.40-44
- Publisher
- Iop Publishing Ltd
- DOI
- 10.1086/522222
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Number of pages
- 5
- Language
- English
- Date published
- 12/10/2007
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984429029602771
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