http://www.ukspaceagency.bis.gov.uk : Herschel digs up the dirt on distant galaxies using cosmic zoom lenses
...Page last updated: 04 November 2010
by the UK Space Agency
The effect of gravitational lensing as seen by Herschel and ground-based telescopes
A UK-led team using the world's largest space telescope, ESA’s Herschel Space Observatory, have discovered a new way of locating a natural phenomenon that acts like a zoom lens, allowing astronomers to peer at galaxies in the distant and early Universe. The magnification created by this phenomenon allows astronomers to see galaxies otherwise hidden from us, providing key insights into how galaxies have changed over the history of the cosmos.
...Dr Mattia Negrello, of the Open University and lead researcher of the study, explained, “Our survey of the sky looks for sources of sub-millimetre light. The big breakthrough is that we have discovered that many of the brightest sources are being magnified by lenses, which means that we no longer have to rely on the rather inefficient methods of finding lenses used at visible and radio wavelengths.”
...Dr Loretta Dunne of Nottingham University and joint-leader of the Herschel-ATLAS survey said, “What we’ve seen so far is just the tip of the iceberg. Wide area surveys are essential for finding these rare events and since Herschel has only covered one thirtieth of the entire Herschel-ATLAS area so far, we expect to discover hundreds of lenses once we have all the data. Once found, we can probe the early Universe on the same physical scales as we can in galaxies next door."
Professor Steve Eales from Cardiff University and the other leader of the survey added: “We can also use this technique to study the lenses themselves. This is exciting because 80% of the matter in the Universe is thought to be dark matter, which does not absorb, reflect or emit light and so can’t be seen directly with our telescopes. With the large number of gravitational lenses that we’ll get from our full survey, we’ll really be able to get to grips with this hidden Universe.”