ROYAL ASTRONOMICAL SOCIETY PRESS INFORMATION NOTE
Ref.: PN 08/12 (NAM 03)
Issued by RAS Press Officers:
Dr Robert Massey
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E-mail: rm(at)ras.org.uk
Anita Heward
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NATIONAL ASTRONOMY MEETING PRESS ROOM (31 MARCH - 4 APRIL ONLY):
Tel: +44 (0)2890 975262
975263
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NAM 2008
http://nam2008.qub.ac.uk
Royal Astronomical Society
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CONTACT DETAILS ARE LISTED AT THE END OF THIS RELEASE
RAS PN 08/12 (NAM 03) (EMBARGOED): STARS BURST INTO LIFE IN THE EARLY
UNIVERSE
New measurements from some of the most distant galaxies bolster the
evidence that the strongest burst of star formation in the history of
the Universe occurred about two billion years after the Big Bang. An
international team of astronomers from the UK, France, Germany and the
USA have found evidence for a dramatic surge in star birth in a newly
discovered population of massive galaxies in the early Universe.
In his talk at the RAS National Astronomy Meeting in Belfast on Tuesday
1 April, team member Dr Scott Chapman from the Institute of Astronomy in
Cambridge will present observations of five of these galaxies that are
forming stars at a tremendous rate and have large reservoirs of gas that
will power the star formation for hundreds of millions of years. Dr
Chapman?s work is supported by a parallel study made by PhD student
Caitlin Casey, who finds that the star formation in the new galaxies is
distributed over a vast area.
The galaxies are so distant that the light we detect from them has been
travelling for more than 10 billion years. This means that we see them
as they were about a three billion years after the Big Bang. The recent
discovery of a new type of extremely luminous galaxy in this epoch - one
that is very faint in visible light, but much brighter at longer, radio
wavelengths - is the key to the new results.
A related type of galaxy was first found in 1997 (but not well
understood until 2003) using a new and much more sensitive camera that
detects radiation emitted at submillimetre wavelengths (longer than the
wavelengths of visible light that we see with but somewhat shorter than
radio waves). The camera, called `SCUBA' was attached to the James Clerk
Maxwell Telescope (JCMT), on Mauna Kea in Hawaii.
In 2004 the Cambridge-led team of astronomers proposed that these
distant "submillimetre-galaxies" might only represent half of the
picture of rapid star formation in the early Universe, as SCUBA is
biased towards colder objects. They suggested that a population of
similar galaxies with slightly hotter temperatures could exist but have
gone largely unnoticed.
The team of scientists searched for the missing galaxies using
observatories around the world: the MERLIN array in the UK, the Very
Large Array (VLA) in the US (both radio observatories), the Keck optical
telescope on Hawaii and the Plateau de Bure submillimetre observatory in
France. The instruments found and pinpointed the galaxies, measured
their distances and then confirmed their star forming nature through the
detection of the vastly extended gas and dust.
The new galaxies have prodigious rates of star formation, far higher
than anything seen in the present-day Universe. They probably developed
after the first stars and galaxies had already formed in what would have
been a perfectly smooth Universe. None the less, studying these new
objects gives astronomers an insight into the earliest epochs of star
formation after the Big Bang.
With the new discovery, the Cambridge astronomers have provided a much
more accurate census of some of the most extreme galaxies in the
Universe at the peak of their activity. Future observations will
investigate the details of the galaxies? power source and try to
establish how they will develop once their intense bursts of activity
come to an end.
IMAGES AND FURTHER INFORMATION
Images and movie
http://www.ast.cam.ac.uk/~ccasey/sfrg.html
Plateau de Bure Interferometer
http://www.iram.fr/IRAMFR/index.htm
MERLIN
http://www.merlin.ac.uk
NOTES FOR EDITORS
The Plateau de Bure Interferometer is managed by IRAM. IRAM is supported
by the Max-Planck-Society, INSU/CNRS (France), and IGN (Spain).
MERLIN is operated by the University of Manchester as a National
Facility of the Science and Technology Facilities Council (STFC).
The RAS National Astronomy Meeting (NAM 2008) is hosted by Queen's
University Belfast. It is principally sponsored by the RAS and the
Science and Technology Facilities Council (STFC). NAM 2008 is being held
together with the UK Solar Physics (UKSP) and Magnetosphere, Ionosphere
and Solar-Terrestrial (MIST) spring meetings.
CONTACTS
Dr Scott Chapman
Institute of Astronomy
University of Cambridge
Madingley Road
Cambridge CB3 0HA
E-mail: schapman(at)ast.cam.ac.uk
Tel: +44 (0)1223 330803
Caitlin Casey
Institute of Astronomy
University of Cambridge
Madingley Road
Cambridge CB3 0HA
E-mail: ccasey(at)ast.cam.ac.uk
Professor Frank Bertoldi
University of Bonn
Bonn
Germany
E-mail: bertoldi(at)astro.uni-bonn.de
Dr Tom Muxlow
Jodrell Bank Observatory
University of Manchester
Macclesfield SK11 9DL
UK
E-mail: twbm(at)jb.man.ac.uk
Professor Ian Smail
Institute for Computational Cosmology
Durham University
South Road
Durham DH1 3LE
UK
E-mail: ian.smail(at)durham.ac.uk
Professor Andrew Blain
California Institute of Technology
Pasadena
CA 91125
E-mail: awb(at)astro.caltech.edu
Professor Rob Ivison
Institute for Astronomy
University of Edinburgh
Royal Observatory
Blackford Hill
Edinburgh EH9 3HJ
UK
E-mail: rji(at)roe.ac.uk
