A new study into where the normal matter produced by the Big
Bang is today, has discovered that twenty percent has already turned
into stars.
The research, led by the University of St Andrews, involved a
survey of over ten thousand giant galaxies, each comprising of up to
10 billion stars as well as bulges, discs and super-massive black
holes. The survey was able to determine how much of the Universe’s
matter is locked away in black holes, some of which are one million
billion times more massive than the Earth. By adding up each key
component they found that the Universe has ‘guzzled’ its way through
about twenty percent of its original fuel reserves.
Project leader Dr Simon Driver of the University of St Andrews
said: "The simplest prognosis is that the Universe will be able to
form stars for a further 70 billion years or so after which it will
start to go dark. However, unlike our stewardship of the Earth, the
Universe is definitely tightening its belt with the rate at which
new stars are forming steadily decreasing."
Tracking down what happened to normal matter dating back to the
Big Bang 14 billion years ago has remained one of the most important
goals for cosmologists for many years. The new survey reveals that
about 20% is locked up in stars, a further 0.1% lies in dust
expelled from the massive stars (and from which solid structures
like the Earth and man are made), and about 0.01% is in the form of
super-massive black holes.
"The remaining 80% are almost completely in gaseous form lying
both within and between the galaxies and constitutes the reservoir
from which future generations of stars may form," Dr Driver
continued.
The survey involved scientists from Australia, Germany and the
UK, and resulted in the Millennium Galaxy Catalogue (MGC),
constructed from over 100 nights of telescope time in the Canary
Islands, Australia and Chile.
“What is new about the MGC is that it focuses on the structures
in which stars are arranged inside galaxies. We have literally
dismantled each galaxy so that we can study the main components
separately,” said Dr Driver.
The survey is the first to catalogue reliable information on the
distances, sizes, colours and shapes of both the bulge and disc
components of so many galaxies. Dr Driver and his team found that on
average half the stars in the Universe lie in the central bulges of
galaxies, while the other half are found in discs surrounding the
bulges.
“By measuring the concentration of stars in each galaxy’s bulge,
we have also been able to determine the super-massive black hole
mass at the heart of each galaxy”, said Dr Alister Graham of the
Australian National University.
“It was then a simple matter of summing these up to determine how
much of the Universe’s matter is locked away in such monstrous black
holes.”
The survey was presented at the General Assembly of the
International Astronomical Union in Prague this week. Financial
support for this project was jointly provided by the UK Particle
Physics and Astrophysics Research Council and the Australian
Research Council.
ENDS
NOTE TO EDITORS: FOR FURTHER INFORMATION CONTACT -
UNITED KINGDOM: Dr Simon Driver, Director of St Andrews'
Observatory, University of St Andrews, St Andrews, Fife, SCOTLAND
Mobile: 0791930 5906 (Friday) +44-(0)1334-461680 (after Friday)
E-mail: spd3@st-and.ac.uk
GERMANY: Dr Jochen Liske, European Southern Observatory,
Garching, GERMANY +49-(0)89-32006582 E-mail: jliske@eso.org
AUSTRALIA: Drs Alister Graham and Paul Allen, The Australian
National University, Canberra, AUSTRALIA +61-(0)2-6125-6713 E-mail:
graham@mso.anu.edu.au & paul@mso.anu.edu.au
MGC website: http://www.eso.org/~jliske/mgc
Issued by Beattie Media – www.beattiegroup.com on behalf of the
University of St Andrews
Contact Gayle Cook, Press Officer on 01334 467227 / 462529,
mobile 07900 050 103, or email gec3@st- andrews.ac.uk
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