| |
 |
Largest cosmic structure mapped out
|
LIKE cosmic lighthouses shining through fog on an astral beach, a clump of quasars lit the way to a supercluster of galaxies that could be the biggest structure of the early universe, astronomers said on Monday in San Diego, Los Angeles, the US.
The galactic-quasar grouping is thought to be about 500 million light years across, with each light year being 6 trillion miles, the distance light travels in a year.
If the cluster were visible with the naked eye from Earth, it would cover a region about two by five degrees in size in the night sky, or about 40 times the area of the full moon, scientists from NASA's Goddard Space Flight Centre and the National Optical Astronomy Observatories in Arizona reported.
Located for viewing purposes in the heart of the constellation Leo the Lion, the galaxies are actually about 6.5 billion light years away. Because in astronomical terms, distance equals time, scientists are seeing the supercluster when the universe was perhaps one-third the age it is now.
The galaxies might not have been apparent at all except for the concentration of quasars behind them, according to Gerard Williger, who presented the findings with colleagues at the annual meeting of the American Astronomical Society in San Diego.
Quasars are galaxies with bright cores, probably powered by matter-sucking black holes, that can shine with the brilliance of a trillion suns. That makes them ideal tools for pinpointing objects between them and Earth, Williger told reporters.
``We haven't found anything bigger in the literature,'' Williger said. ``And nobody has brought anything bigger to our attention.''(SD-Agencies)
|
|
|
|
