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Astronomical excitement
Prof Carlos Frenk on the galactic gift
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Friday, 29 June, 2001, 23:01 GMT 00:01 UK
A 'gift of galaxies'
The survey maps the galaxies in two directions in space
By BBC News Online science editor Dr David Whitehouse

In a giant map, astronomers have seen faint waves of galaxies that may have their origin in tiny ripples in the gases of the young Universe.

Scientists believe that such ripples were the seeds for all the structures - galaxies, stars, planets - that we see in the cosmos today.

What we are doing now is reaping the fruit that's been growing through 10 billion years of cosmic evolution

Carlos Frenk, University of Durham
The faint waves were seen within a map of 100,000 galaxies just about to be released on the internet. It is the largest and most detailed survey of the galaxies ever conducted.

Astronomers say the repository of data has parallels with that from the mapping of the human genome, also available on the internet.

"One is the blueprint for mankind, the other is the blueprint for the Universe," said one scientist.

'Very excited'

An international team of astronomers has mapped the positions of over 100,000 galaxies, revealing great clusters and "spiderweb" patterns in our local region of the Universe.

The initiative is called the 2dF (two-degree Field) survey and was carried out in Australia. It measured the so-called redshift of the galaxies from which their distance can be inferred.

Galaxies are not strewn at random across space
Designed and built by the Anglo-Australian Observatory, the 2dF is one of the world's most complex astronomical instruments, able to capture 400 spectra simultaneously.

A robot arm positions up to 400 optical fibres on a field plate, on to which light from up to 400 objects is focused.

"The 2dF dataset is a free gift of 100,000 redshifts to astronomers world-wide. They can apply it immediately to improving our understanding of galaxy evolution and the structure of the Universe," said 2dF survey team co-leader Dr Matthew Colless, of the Australian National University.

A key finding from the data is the first firm evidence that the irregularities seen in the ancient cosmic microwave background are still imprinted on the distribution of galaxies in today's Universe.

'Cosmic evolution'

It has been observed because the large sample of galaxies has allowed researchers to measure the distribution of galaxies to a high degree of precision.

"These subtle over-densities in the galaxy distribution range in size from about 300 million to 1.5 billion light-years," said Professor John Peacock of the University of Edinburgh, UK.

Professor Carlos Frenk, of the University of Durham, UK, said: "We are very excited by this. For the first time, we have a convincing connection between the initial state of the Universe as probed by the microwave background and the present Universe as probed by the galaxies.

"What we are doing now is reaping the fruit that's been growing through 10 billion years of cosmic evolution," he added.

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See also:

12 May 00 | Sci/Tech
Close-up on the early Universe
27 Oct 00 | Sci/Tech
Hubble solves cosmic mystery
09 Jan 01 | Sci/Tech
Huge galaxy grouping detected
19 May 00 | Sci/Tech
Voyage through the Universe
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