CMB cold spot

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The cold spot in the data of WMAP - probe
Correlation between the supervoid and the temperature of the background radiation

The CMB Cold Spot or WMAP Cold Spot , also Eridanus Supervoid , is a region of the sky in the constellation Eridanus in which the cosmic microwave background radiation (CMB) has an unusually extensive and unusually large deviation from the mean: the "cold spot" is about 70 µ K colder than the mean of the CMB temperature (approx. 2.7 K), whereby the root mean square value of typical temperature fluctuations is only 18 µK.

One possible explanation for the cold spot is a huge void (called a supervoid ) between it and the earth. The radiation that reaches the earth through the more material regions next to this void has a higher energy due to the Sachs-Wolfe effect than that which has passed through the supervoid. Therefore, this region appears cooler.

Individual evidence

  1. ^ EL Wright: Theoretical Overview of Cosmic Microwave Background Anisotropy . In: Astrophysics . May 29, 2003, arxiv : astro-ph / 0305591 .
  2. ^ WL Freedman: Measuring and Modeling the Universe. Cambridge University Press , 2004, ISBN 0-521-75576-X , p. 291 ff.