SCIENTISTS USE 20 BILLION YEAR OLD QUASAR AS FLASHLIGHT;
FIND TRACES OF INTERGALACTIC WEB OF GAS AND DARK MATTER
Based on reports (both dated 19 January 2014) in Nature News (Light from ancient quasar reveals intergalactic web) and in NewScientist (Giant flashlight illuminates cosmic network).
IMAGES: [1] Nature 380 (18 April 1996) [2] S.Cantalupo The quasar UM 287 (bright spot at the centre) shines light on the largest gas cloud ever seen in the Universe. [3] S. Cantalupo This 10 million light year-wide section of a simulation of the early Universe shows how matter coalesces into galaxies connected by filaments of rarefied gas.
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Astronomers have discovered the largest known gas cloud in the Universe. Using light from the activity of a distant supermassive black hole, they imaged an enormous strand of gas held together by invisible dark matter. This mammoth nebula may be one filament of a spiderweb of galaxies, gas and dark matter that traces the large-scale structure of the cosmos.
Simulations of the evolution of the universe have suggested that, as the universe cooled after the big bang, dark matter settled into a network of filaments that criss-crossed the cosmos. The greater gravity at points where these strands crossed drew in ordinary matter, which eventually grew dense enough to ignite stars and develop galaxies and galaxy clusters
See Nature 380 (18 April 1996): How filaments of galaxies are woven into the cosmic web.
The gas cloud could be one of the filaments that stretched between galaxies in the early universe.
The quasar UM 287 is 10 billion light years away, so its light comes from when the universe was relatively young. The filament it illuminates is 2 million light years across, large enough that it must extend from UM 287's host galaxy into intergalactic space.
"We always had this picture of the cosmic web in mind, and we had some ideas of connecting the galaxies," says astronomer Sebastiano Cantalupo (University of California, Santa Cruz and the Lick Observatory). "But the way to really see if the gas is in a filament or a different morphology – in clumps, in a ball, in a sphere – is to look in emission. This is in a sense the first image that we have of the cosmic web."
Read the report in Nature ...
Read the complete report in NewScientist ...
Check out the abstract of the paper by Cantalupo et al, A cosmic web filament revealed in Lyman-α emission around a luminous high-redshift quasar ...
