NEWS & PRESS
ROYAL ASTRONOMICAL SOCIETY PRESS INFORMATION NOTE
Date: 9 January 2008
Ref.: PN 08/03
EMBARGOED UNTIL 0001 GMT, FRIDAY 11 JANUARY 2008
Forwarded from Durham University Media Office by:
Dr Robert Massey
Royal Astronomical Society
London W1J 0BQ
Tel: +44 (0)20 7734 3307 / 4582
Mob: +44 (0)794 124 8035
RAS PN 08/03: SUPERCOMPUTER COULD THROW LIGHT ON DARK ENERGY
Cosmologists at Durham University’s world-leading Institute for Computational Cosmology (ICC) have run a series of huge computer simulations of the Universe that could help solve one of astronomy’s greatest mysteries. The results tell researchers how to measure dark energy – a force that counteracts gravity and could decide the ultimate fate of the cosmos.
The findings, to be published on Friday, 11 January in the Monthly Notices of the Royal Astronomical Society, will also provide vital input into the design of a proposed satellite mission called SPACE – the SPectroscopic All-sky Cosmic Explorer - that could unveil the nature of dark energy.
The discovery of dark energy in 1998 was completely unexpected and understanding its nature is one of the biggest problems in physics. Scientists believe that dark energy, which makes up 70 per cent of the Universe, is driving its accelerating expansion. If this expansion continues to accelerate experts say it could eventually lead to a Big Freeze as the Universe is pulled apart and becomes a vast cold expanse of dying stars and black holes.
The simulations, which took 11 days to run on Durham’s unique Cosmology Machine (COSMA) computer, looked at tiny ripples in the distribution of matter in the Universe made by sound waves a few hundred thousand years after the Big Bang. The ripples are delicate and some have been destroyed over the subsequent 13 billion years of the Universe, but the simulations showed they survived in certain conditions.
By changing the nature of dark energy in the simulations, the researchers discovered that the ripples appeared to change in length and could act as a “standard ruler” in the measurement of dark energy.
ICC Director Professor Carlos Frenk said: “The ripples are a ‘gold standard’. By comparing the size of the measured ripples to the gold standard we can work out how the Universe has expanded and from this figure out the properties of the dark energy.
“Astronomers are stuck with the one universe we live in. However, the simulations allow us to experiment with what might have happened if there had been more or less dark energy in the universe.”
In the next five to 10 years a number of experiments are planned to explore dark energy. The Durham simulation has demonstrated the feasibility of the SPACE satellite mission proposed to the European Space Agency’s (ESA) Cosmic Vision programme.
The project has been put forward by an international consortium of researchers including the Durham team.
SPACE, which is led by Bologna University, in Italy, is through to the next round of assessment by the ESA and if successful is planned to launch in 2017.
Co-principal investigator Professor Andrea Cimatti, of Bologna University, said: “Thanks to the ICC simulations it is possible to predict what SPACE would observe and to plan how to develop the mission parameters in order to obtain a three-dimensional map of the Universe and to compare it with the predictions of the simulations.
“Thanks to this comparison it will be possible to unveil the nature of dark energy and to understand how the structures in the Universe built up and evolved with cosmic time.”
The Durham research was funded by the Science and Technology Facilities Council (STFC) and the European Commission.
IMAGES of the simulation results are available from Durham University Media Office.
Details of paper:
About the Institute of Computational Cosmology (ICC):
The ICC, part of the Ogden Centre for Fundamental Physics at Durham University, is a leading international centre for research into the origin and evolution of the Universe. For more details visit http://www.icc.dur.ac.uk/
SPACE – the Spectroscopic All-sky Cosmic Explorer http://urania.bo.astro.it/cimatti/space/
The announcement of the European Space Agency’s Cosmic Vision shortlist can be found at http://sci.esa.int/science-e/www/area/index.cfm?fareaid=100
NOTES FOR EDITORS
The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organizes scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.