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Institute for Computational Cosmology
ICC News Summer Science RAS Awards
Research Overview of ICC research themes
Ogden@10 10th Anniversary of the ICC
COSMA V New installation of Cosmology Machine
July 2013
Cosmology in Crisis: What is the matter?
Astronomy Picture of the Day 12th October 2012
Discover the cosmos! Each day a different image or
photograph of our fascinating universe is featured, along
with a brief explanation written by a professional
astronomer.
Pan-STARRS and Nebulae
Image Credit: PS1 Science Consortium
Processing: Nigel Metcalfe, Peter Draper (Durham Univ.),
Gene Magnier (IfA Hawaii)
Explanation: A single field from the world's most
powerful survey instrument captures this spectacular
skyview. Looking toward Sagittarius, the scene spans
nearly 3 degrees or six times the width of the Full Moon.
At bottom, upper right, and lower left it covers the Lagoon
Nebula (M8), the Trifid Nebula (M20), and NGC 6559, in
the crowded, dusty starfields of the central Milky Way.
The adopted color scheme shows dust reddened starlight
in red hues and normally red emission from hydrogen
atoms in green. Built and operated by the Pan-STARRS
project, the instrument features a 1.4 gigapixel (billion
pixel) digital camera and telescope. Pan-STARRS, the
Panoramic Survey Telescope & Rapid Response
System, is intended to scan the skies for potentially
dangerous near-earth asteroids and comets, exploring http://apod.nasa.gov/apod/ap121012.html (NASA APOD)
ICC NEWS July 2013 icc.dur.ac.uk
Written and designed by: Carlton Baugh
Image, text credits: Mark Lovell, Till Sawala, Richard Bower, Virgo
Consortium, Durham University, IBM, Baojiu Li, ITN News, Euclid
Consortium, Royal Astronomical Society.
“Durham University plays a starring role in computational cosmology”
Case Study reproduced with permission from IBM Systems and
Technology.
Institute for Computational Cosmology. All rights reserved.
ICC NEWS
“The Ogden Centre is a
world-class centre for
research into the
fundamental mysteries
of modern science, from
the properties of the
smallest elementary
particles to the structure
of our Universe as a
whole…”
- Prof Carlos Frenk, ICC Director
In This Issue
ICC news
Research at the ICC
Ogden@10
Cosmology Machine
A PhD at the ICC
The Ogden Centre and the Cosmology Machine
Welcome to the first ICC news! To coincide with the Royal Society’s Summer Science Exhibition in July 2013, we
are delighted to release the first ever issue of the Institute for Computational
Cosmology Newsletter. The past year has been very busy, with events ranging
from the 10th Anniversary of the Ogden Centre for Fundamental Physics to the
latest installation of the Cosmology Machine supercomputer. ICC News brings you
up to date with all the recent activity at the ICC and explains our research and
outreach.
What is the ICC? The Institute for Computational Cosmology (ICC) is a leading international centre
for research into the origin and evolution of the Universe based at Durham
University. We address some of the most fundamental questions in science: What
were the first objects in the Universe? How do galaxies form? What is the nature
of the dark matter and dark energy? Where does the large-scale structure of the
universe come from? What is the fate of the Universe?
The ICC is housed in the Ogden Centre for Fundamental Physics, named after the
benefactor businessman and Durham physics graduate Professor Sir Peter
Ogden. The Ogden Centre is also home to the Institute for Particle Physics
Institute for Computational Cosmology Newsletter July 2013
ICC at Summer Science 2013 The Royal Society’s annual Summer Science Exhibition showcases the most
exciting cutting-edge science and technology research. The Exhibition is the
Society's main public event of the year and is open to members of the general
public as well as students and teachers, scientists, policymakers and the media.
Cosmology in Crisis: What is the Matter? The ICC, along with collaborators from the Virgo Consortium and Nick Holliman’s
Visualisation Lab, was awarded a place at Summer Science 2013 to present our
latest research into the identity of the dark matter, which is generally thought to be
a “cold”, weakly interacting elementary particle. ICC researchers, working with the
Virgo Consortium, have created computer simulations to model how dwarf
galaxies formed, testing their assumptions about the nature of the dark matter.
The team found that the final results of these simulations did not at all match what
we observe. The models showed many more small galaxies in a wide halo around
the Milky Way, whereas in reality there are fewer, larger dwarf galaxies.
So what does this mean for dark matter? One possible explanation is that Cold Dark Matter (CDM) does not exist, and the
predictions of the standard model relating to it are false.
Instead of "cold" dark matter that formed within the first one millionth of a second
after the Big Bang, the Universe may instead be filled with warm dark matter
(WDM). The WDM would have formed later, up to minutes after the Big Bang, and
is described as "warm" as the particles would be lighter and more energetic.
When simulations of galaxy formation are run with WDM instead of CDM, the halo
of dwarf galaxies has the same structure as we observe. Perhaps we need to
change our ideas about dark matter at a fundamental level.
Awards for ICC staff
BIERMANN LECTURER
Prof Carlos Frenk
The Biermann lectures bring world-class theoretical and computational astrophysicists to Garching.
This year's Biermann lecturer
is Prof. Carlos Frenk, who has worked closely with scientists at the Max-Planck-Institute for Astrophysics for almost two decades, trying to understand the evolution of cosmic structure.
RAS FOWLER AWARD
Dr Mark Swinbank
For developing new techniques to study high redshift galaxies, for example coupling integral field spectrographs with adaptive optics and
spatial magnification from gravitational lensing to gain extra
detail of these distant objects.
RAS WINTON CAPITAL AWARD
Dr Baojiu Li
Baojiu Li is a world leader in the field of explanations of the accelerating expansion of the universe that are alternatives to the standard
LCDM model.
A galactic halo simulated with cold dark matter (left) and warm dark matter (right)
Recreating the Universe with the Cosmology
Machine
"We have a world-
leading research base in
the UK, thanks to
excellent institutions like
Durham. Today’s visit
has provided an insight
into the range of exciting
projects at the
university.”
- David Willetts, Minister of
State for Universities and
Science
The Rt. Hon. David Willetts (left) , Carlos Frenk (centre) and Simon Pendlebury (IBM; right)
David Willetts visits Durham The Minister of State for Universities and Science, David Willetts, visited Durham
University to see research projects made possible by government and private
investment. He also unveiled a new £3.7 million supercomputer.
The computer, which is one of the most powerful in the country, is being used to
run simulations of the Big Bang, the birth of the universe, through to the present
day. Scientists at the Institute of Computational Cosmology (ICC) hope it will
explain how the universe works.
Professor Carlos Frenk, Director of the ICC said: "Modern scientific research, from
recreating the evolution of the universe to designing life-saving drugs, relies
heavily on supercomputing - the ``new mathematics'.' The machine opened today
by the Minister of State is one of the most powerful in the UK and will be wholly
dedicated to science." (Reproduced from ITN North East News)
Euclid Mission
ICC researchers joined 400 scientists and
engineers from across Europe and the USA at
the recent Euclid Consortium meeting held in
Leiden.
Euclid is a Medium-class mission of the
European Space Agency which aims to
measure the properties of dark energy.
Although Euclid is scheduled for launch in
2019, there is still a huge amount of work to do
beforehand, and Durham is helping to lead the
way!
ICC RESEARCH
The flagship of Durham Galaxy formation simulations is the EAGLE project. It builds
on two of our earlier simulations of the universe : the GIMIC simulation (carried out
at the ICC, Crain et al. 2009) and OWLS (carried out in collaboration with
astronomers at Leiden University, Schaye et al 2010). These simulations showed
that it was possible to incorporate the main processes of galaxy formation into a
computer simulations, and that it was possible to simultaneously achieve sufficient
resolution to create realistic-looking galaxies and to model a sufficiently large
cosmological volume that the results were representative of the universe as a whole.
The EAGLE (Evolution of Galaxies and their Environment) simulations push the
ideas presented in GIMIC and OWLS to the next level.
This image, measuring 50 Mpc across, shows the formation
of a cluster of galaxies in the Eagle simulation. The colours
show gas at different temperatures from cold 10 000 K (blue),
warm (100,000 K, green) to hot (>1,000,000 K) gas. The main
structure is created by the gravitational skeleton of dark
matter. Galaxies form a knots in these filaments heating the
surrounding gas and creating the fluffy appearance. The
large, hot bubbles are created by feedback from black holes
in the largest galaxies.
“The simulations make a
remarkably realistic virtual
universe. We believe that they
are unique in the accuracy
with which they describe the
universe around us…”
- Prof Richard Bower
BUILDING A UNIVERSE OF GALAXIES
REDESIGNING GRAVITY “Understanding gravity is one of the
frontiers of physics. Although
Einstein’s theory of general relativity
has been tested to high accuracy, the
tests have so far been restricted to
rather small scales, such as the solar
system. To apply this theory on
cosmological scales is a remarkable
extrapolation of what is known”
- Dr Baojiu Li
The images show the density fields (top panels) in
different modified gravity models, called f(R) gravity.
The models approach standard gravity moving from
left to right. The bottoms panels show the
Newtonian potential Φ in the same simulations. The
middle panels show the scalaron field which
governs the modification to gravity.
GALACTIC ARCHEOLOGY Simulations have been carried out to predict which satellite haloes in the
Aquarius simulations of Milky Way mass halos (shown here in purple)
will host dwarf galaxies. Some of these satellites are pulled apart by tidal
forces as they orbit inside the Milky-Way like dark haloes. This image
shows (in blue and yellow) the 'debris' of these shredded galaxies, visible
in faint clouds and huge 'ghostly' streams. Streams and clouds like these
have already been seen around the Milky Way, and our simulations
predict that many more are waiting to be discovered. The properties of
these streams are a test of the 'lost' population of satellite galaxies, which
might not be the same as those that still survive.
“The work of Durham University ranks at #22 among the 140 institutions comprising the top 1% in
the field of Space Science. Durham's current record in this field includes 1,278 papers cited a to-
tal of 48,057 times between January 1, 2000 and October 31, 2010. “
—Essential Science Indicators from Thomson Reuters
A census of where the baryons are at the present day shows that only a very small fraction is in stars, cold gas that
can be detected in absorption or emission, or hot gas in clusters that emits X-rays, meaning that most of it must be in
some yet undetected form. Hydrodynamical simulations like the one above show that indeed at the present day the
majority of baryons is in a relatively low-density warm-hot phase, called the WHIM. Such low-density ionised gas is
very difficult to detect. The image shows the results of one such numerical simulation, in which we compute how
strongly the WHIM radiates in Oxygen-VI — the colours show the intensity of the line emission. This UV-emission line
traces the filamentary structure of the large-scale matter distribution. We have investigated the surface brightness for
a large number of UV and X-ray emission lines, and also qualified how uncertainties in the modelling affect our
results. These results can be used to design future space missions that will look for the missing baryons.
GAS BETWEEN GALAXIES
LIGHTING UP THE DARK MATTER Modelling the formation and evolution of galaxies is one of the toughest
challenges in astrophysics as it requires many nonlinear processes to be
followed, such as star formation and heating by AGN, which operate over vast
ranges of length, time and mass scales. At the ICC, we pursue complementary
routes to study how galaxies are made, which can be divided into gas dynamics
simulations and semi-analytical modelling:
The ICC is one of the pioneers of the semi-analytical approach to modelling
galaxy formation. The current semi-analytical code, GALFORM, makes an ab
initio prediction of the star formation, merger and chemical enrichment histories of
galaxies. GALFORM is implemented in high-resolution, large-volume N-body
simulations of the hierarchical clustering of the dark matter, to predict the spatial
distribution of galaxies. Such calculations are used to build mock catalogues for
galaxy surveys such as Pan-STARRS and Euclid.
The images show the distribution of dark matter (top) in the Millennium Simulation
and the location of the galaxies, (bottom panel) as predicted by GALFORM.
Contact Us
Postal address:
Institute for Computational Cosmology, Ogden Centre for Fundamental Physics, Department of Physics, Durham University, Science Laboratories, South Road, Durham, DH1 3LE. UK.
Telephone and Email:
Mrs. D.M.Jenkins (Secretary)
Tel: +44 (0)191 334 3635,
Fax:+44 (0)191 334 3645
Email:
Visit us on the web at
icc.dur.ac.uk
The next generation The ICC has an outstanding track record of training young researchers,
offering access to world leading expertise and state of the art resources.
Students and postdocs work in a collaborative and supportive
environment.
Durham provides the opportunity to participate in international
collaborations. In addition to the Virgo Consortium for Cosmological
Simulations, the ICC plays leading roles in international surveys,
including Pan-STARRS, Herschel, GAMA, SCUBA-II and Euclid. We are
also the coordinating node of two Marie-Curie funded training programs,
CosmoComp and LACEGAL.
Studying for a PhD at the ICC
The postgraduate student body at the ICC is truly international (with
representatives from China, Crete, Portugal, Ireland, Chile, Mexico,
USA, Germany, Switzerland and, of course, the UK).
Around half of the places we offer are supported by STFC-funded PhD
studentships: the remainder are funded by a range of different sources
(e.g. ERC, non-UK government).
Students undertake full-time cutting edge astronomical research, in
addition to our post-graduate lecture courses in their first year.
The STFC-funded PhD studentships cover course fees and living
expenses for 3.5 years. Applicants are required to have, or expected to
gain, at least a 2.1 in an integrated MPhys or a pass in a Masters degree
or a 1st class in a Bachelors degree, in physics, astrophysics or
mathematics.
Further details and information about how to apply can be found at:
http://icc.dur.ac.uk/index.php?content=Postgraduate/Postgraduate