Hannah Devlin in the April 21st 2015 edition of The Guardian reports on a paper published
in the Monthly Notices of the Royal Astronomical Society entitled
"Detection of a supervoid aligned with the cold spot of the cosmic microwave background".
See
http://www.theguardian.com/science/2...-is-a-big-hole
See
http://mnras.oxfordjournals.org/content/450/1/288
Quote:
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Originally Posted by Hannah Devlin, Science Correspondent, The Guardian
The “supervoid”, as it is known, is a spherical blob 1.8 billion light years across that is distinguished by its unusual emptiness.
István Szapudi, who led the work at the University of Hawaii at Manoa, described the object as possibly “the largest individual structure ever identified by humanity”.
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Szapudi’s team was intentionally searching for the void because they believed that it could explain previous observations showing that part of the sky is unusually cool.
The so-called Cold Spot was discovered 10 years ago and has proved a sticking point for the best current models for how the universe evolved following the Big Bang. Cosmological theory allows for a bit of patchiness in the background temperature, due to warmer and cooler spots of various sizes emerging in the infant universe, but areas as large and cold as the Cold Spot are unexpected.
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The supervoid is not an actual vacuum, as its name suggests, but has about 20% less stuff in it than our part of the universe – or any typical region. “Supervoids are not entirely empty, they’re under-dense,” said András Kovács, a co-author at the Eötvös Loránd University in Budapest.
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The observation that the Cold Spot and supervoid coincide would fit with the idea that the universe is indeed expanding at an accelerating rate, which scientists put down to forces linked to dark energy. “This is independent evidence, in case anyone doubts it, for the existence of dark energy,” said Frenk.
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