thed
04-14-02, 08:12 AM
Oops, wtong image.
<img SRC="http://www.roe.ac.uk/~meg/darkmatter/imgs/Dark_Matter_Analysis.jpg" NOSAVE ALT="A901/902 Dark Matter Map" height=540 width=720>
Royal Astronomical Society Press Notice
Date: 3 April 2002
EMBARGOED FOR 7 am BST, WEDNESDAY 10 APRIL 2002
Ref. PN 02/17 (NAM 11)
Issued by: RAS Press Officers
Peter Bond (Except 8 - 12 April)
Tel: +44 (0)1483-268672
Fax: +44 (0)1483-274047
Mobile phone: +44 (0)7711-213486
E-mail: PeterRBond@cs.com
AND
Dr Jacqueline Mitton (Except 7 - 13 April)
Tel: +44 (0)1223-564914
Fax: +44 (0)1223-572892
E-mail: jmitton@dial.pipex.com
Mobile phone: +44 (0)7770-386133
NAM PRESS ROOM (9 -12 April only):
+44 (0)117 928-4337
+44 (0)117 928-4338
+44 (0)117 954-5913
+44 (0)117 928-7901
RAS Web site: http://www.ras.org.uk
UK National Astronomy Meeting Web site:
http://www.star.bris.ac.uk/nam/index.html
CONTACT DETAILS ARE LISTED AT THE END OF THIS RELEASE.
************************************************** **********
MAPPING THE COSMIC WEB OF DARK MATTER
What is Dark Matter and where is it found? These are two of the major
mysteries in current studies of the Universe.
Although the nature of this invisible material remains elusive,
astronomers are beginning to produce detailed maps of the Cosmos,
showing its location in relation to the ordinary matter that we can
see in telescopes.
One of the world leaders in this research is Dr. Andrew Taylor (Royal
Observatory, Edinburgh), who will be presenting the most accurate
image ever obtained of the Dark Matter in a galactic supercluster at
the UK National Astronomy Meeting in Bristol on Wednesday 10 April
2002.
"Ultimately we hope that the detection of a Dark Matter particle in a
laboratory will reveal its true nature and place in physics," said Dr.
Taylor. "But at the moment our only guide to the properties of the
Dark Matter is from Cosmology."
The method used by Taylor, a PPARC Advanced Fellow, Dr. Meghan Gray,
then a student at the Institute of Astronomy in Cambridge, and
co-workers in Heidelberg and Imperial College London, is to take
advantage of gravitational lensing, when light from a distant galaxy
is bent by the gravitational field of matter in front of it. Such
gravitational lenses provide a direct probe of where Dark Matter is
in the Universe.
Edinburgh has long been at the forefront of developing and applying
methods of using gravitational lensing to image the two-dimensional
distribution of Dark Matter and so study its properties.
In a recent study, Taylor and his colleagues have made the most
detailed analysis yet of the Dark Matter in the Abell 901/2
supercluster, one of the largest structures in the Universe. The
enormous structure, some 10 million light years across, contains a
group of galaxy clusters known as Abell 901a, 901b and Abell 902.
Their image of the Dark Matter, which covers an area of sky the size
of the full Moon, was obtained by analysing the gravitationally
lensed images of 50,000 galaxies. It shows that not only do the
galaxies we see lie within larger Dark Matter clumps, but that these
clumps are connected by "cosmic filaments" -- bridges of Dark Matter
connecting the clusters.
The existence of these filaments has long been a prediction of the
theory of Dark Matter in the Universe, which indicated that the
matter in the Universe is distributed in an intricate network of
clumps and filaments -- the so-called Cosmic Web.
More recently Taylor has developed a new method which will allow
cosmologists for the first time to make fully three-dimensional
images of the Dark Matter distribution in the Universe using
gravitational lensing (Ref: Taylor, 2002, submitted to Phys Rev
Lett, http://arXiv.org/abs/astro-ph/0111605).
"Having 3-D images will allow cosmologists to put much better
constraints on the nature of Dark Matter in the Universe," explained
Taylor.
NOTE FOR EDITORS:
The existence of invisible Dark Matter has been determined from its
gravitational pull on stars and galaxies. Calculations suggest that
it fills the Universe, making up 80% of all of the matter in the
Universe, and is five times more abundant than ordinary matter.
When it clumps together it seeds the formation of galaxies. Its
gravitational pull also holds together clusters of galaxies.
Details of the supercluster research were published in the March 20th
issue of the Astrophysical Journal. (Ref: Gray & Taylor et al, 2002,
ApJ, 568, 141-162, http://arXiv.org/abs/astro-ph/0111288).
The Royal Observatory, Edinburgh (ROE) comprises the UK Astronomy
Technology Centre of the Particle Physics and Astronomy Research
Council (PPARC), the Institute for Astronomy of the University of
Edinburgh and the ROE Visitor Centre.
CONTACT DETAILS:
During the National Astronomy Meeting, Dr. Taylor can be contacted via
the NAM press office (see above)
Normal contact details:
Dr. Andrew N. Taylor
Institute for Astronomy
University of Edinburgh
Royal Observatory
Blackford Hill
Edinburgh
EH9 3HJ
Tel: +44 (0)131-668-8298
Fax: +44 (0)131-668-8416
E-mail: ant@roe.ac.uk
AN IMAGE SHOWING THE DARK MATTER FILAMENTS IN SUPERCLUSTER ABELL 901/2 IS
AVAILABLE ON THE WEB AT:
http://www.roe.ac.uk/~meg/darkmatter/supercluster.html
<img SRC="http://www.roe.ac.uk/~meg/darkmatter/imgs/Dark_Matter_Analysis.jpg" NOSAVE ALT="A901/902 Dark Matter Map" height=540 width=720>
Royal Astronomical Society Press Notice
Date: 3 April 2002
EMBARGOED FOR 7 am BST, WEDNESDAY 10 APRIL 2002
Ref. PN 02/17 (NAM 11)
Issued by: RAS Press Officers
Peter Bond (Except 8 - 12 April)
Tel: +44 (0)1483-268672
Fax: +44 (0)1483-274047
Mobile phone: +44 (0)7711-213486
E-mail: PeterRBond@cs.com
AND
Dr Jacqueline Mitton (Except 7 - 13 April)
Tel: +44 (0)1223-564914
Fax: +44 (0)1223-572892
E-mail: jmitton@dial.pipex.com
Mobile phone: +44 (0)7770-386133
NAM PRESS ROOM (9 -12 April only):
+44 (0)117 928-4337
+44 (0)117 928-4338
+44 (0)117 954-5913
+44 (0)117 928-7901
RAS Web site: http://www.ras.org.uk
UK National Astronomy Meeting Web site:
http://www.star.bris.ac.uk/nam/index.html
CONTACT DETAILS ARE LISTED AT THE END OF THIS RELEASE.
************************************************** **********
MAPPING THE COSMIC WEB OF DARK MATTER
What is Dark Matter and where is it found? These are two of the major
mysteries in current studies of the Universe.
Although the nature of this invisible material remains elusive,
astronomers are beginning to produce detailed maps of the Cosmos,
showing its location in relation to the ordinary matter that we can
see in telescopes.
One of the world leaders in this research is Dr. Andrew Taylor (Royal
Observatory, Edinburgh), who will be presenting the most accurate
image ever obtained of the Dark Matter in a galactic supercluster at
the UK National Astronomy Meeting in Bristol on Wednesday 10 April
2002.
"Ultimately we hope that the detection of a Dark Matter particle in a
laboratory will reveal its true nature and place in physics," said Dr.
Taylor. "But at the moment our only guide to the properties of the
Dark Matter is from Cosmology."
The method used by Taylor, a PPARC Advanced Fellow, Dr. Meghan Gray,
then a student at the Institute of Astronomy in Cambridge, and
co-workers in Heidelberg and Imperial College London, is to take
advantage of gravitational lensing, when light from a distant galaxy
is bent by the gravitational field of matter in front of it. Such
gravitational lenses provide a direct probe of where Dark Matter is
in the Universe.
Edinburgh has long been at the forefront of developing and applying
methods of using gravitational lensing to image the two-dimensional
distribution of Dark Matter and so study its properties.
In a recent study, Taylor and his colleagues have made the most
detailed analysis yet of the Dark Matter in the Abell 901/2
supercluster, one of the largest structures in the Universe. The
enormous structure, some 10 million light years across, contains a
group of galaxy clusters known as Abell 901a, 901b and Abell 902.
Their image of the Dark Matter, which covers an area of sky the size
of the full Moon, was obtained by analysing the gravitationally
lensed images of 50,000 galaxies. It shows that not only do the
galaxies we see lie within larger Dark Matter clumps, but that these
clumps are connected by "cosmic filaments" -- bridges of Dark Matter
connecting the clusters.
The existence of these filaments has long been a prediction of the
theory of Dark Matter in the Universe, which indicated that the
matter in the Universe is distributed in an intricate network of
clumps and filaments -- the so-called Cosmic Web.
More recently Taylor has developed a new method which will allow
cosmologists for the first time to make fully three-dimensional
images of the Dark Matter distribution in the Universe using
gravitational lensing (Ref: Taylor, 2002, submitted to Phys Rev
Lett, http://arXiv.org/abs/astro-ph/0111605).
"Having 3-D images will allow cosmologists to put much better
constraints on the nature of Dark Matter in the Universe," explained
Taylor.
NOTE FOR EDITORS:
The existence of invisible Dark Matter has been determined from its
gravitational pull on stars and galaxies. Calculations suggest that
it fills the Universe, making up 80% of all of the matter in the
Universe, and is five times more abundant than ordinary matter.
When it clumps together it seeds the formation of galaxies. Its
gravitational pull also holds together clusters of galaxies.
Details of the supercluster research were published in the March 20th
issue of the Astrophysical Journal. (Ref: Gray & Taylor et al, 2002,
ApJ, 568, 141-162, http://arXiv.org/abs/astro-ph/0111288).
The Royal Observatory, Edinburgh (ROE) comprises the UK Astronomy
Technology Centre of the Particle Physics and Astronomy Research
Council (PPARC), the Institute for Astronomy of the University of
Edinburgh and the ROE Visitor Centre.
CONTACT DETAILS:
During the National Astronomy Meeting, Dr. Taylor can be contacted via
the NAM press office (see above)
Normal contact details:
Dr. Andrew N. Taylor
Institute for Astronomy
University of Edinburgh
Royal Observatory
Blackford Hill
Edinburgh
EH9 3HJ
Tel: +44 (0)131-668-8298
Fax: +44 (0)131-668-8416
E-mail: ant@roe.ac.uk
AN IMAGE SHOWING THE DARK MATTER FILAMENTS IN SUPERCLUSTER ABELL 901/2 IS
AVAILABLE ON THE WEB AT:
http://www.roe.ac.uk/~meg/darkmatter/supercluster.html