“Shaped by the Past Creating the Future”

“Shaped by the past creating the future”

The Institute for Computational Cosmology 2012 The Ogden Centre

The Ogden Centre is a multi-million pound initiative to create a centre of excellence in fundamental physics research at the University of Durham.

Opened in autumn 2002 by Physics Phenomenology the Prime Minister, Tony (IPPP), deals with the sub- Blair, the Centre combines atomic world of electrons research into the building and quarks. The Centre’s blocks of the universe, with third role is to draw on cur- a mission to inspire a new rent research to develop generation of young scien- new teaching materials for tists. Its aims reflect the schools, and to stimulate interests of Peter Ogden, young people to aspire to the principal private donor be the scientists of tomor- who was inspired by his row. own physics teacher at school to read the subject The research programme at Durham University. of the ICC encompasses all aspects of cosmogony, The Centre has three main from the birth of the first functions. It provides state- objects in the Universe to of-the-art accommodation the physics of galaxy for- for two scientific teams, mation. Its long term goals each working at the fore- are to understand the ori- front of research at oppo- gin of structure in the Uni- site ends of the known verse, to establish the physical scale. At one ex- identity and properties of treme, the Institute for dark matter and dark en- Computational Cosmology ergy which dominate our (ICC) probes the past, pre- Universe and to relate sent and possible future theoretical predictions to development of the Uni- astronomical observations. verse. At the other, the Institute for Particle

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.

Professor Carlos Frenk FRS Director of the ICC ” 2 ICC The past twenty years have seen the emergence of a paradigm for the geometry and content of our Universe, and for the origin and evolution of all structure within it. According to this Lambda-CDM model, we live in a flat universe where about two thirds of the mass-energy is now in a dark energy field that drives the observed acceleration of the cosmic expansion, about a quarter is dark matter, most probably a new weakly interacting elementary particle, and only about 5 percent is bary- onic matter, of which only about a tenth is in stars today and the rest resides mostly in the intergalactic medium. Structure was seeded by quantum fluctuations at early Research at the ICC times. These produced weak sound waves in the primordial plasma that left observable imprints on the sur- face of recombination, seen when the universe was only 400,000 years old. These ripples, mapped by imaging the cosmic microwave background radiation, grew into the full richness of structure we see around us. Today ICC researchers have played a central role in the development and acceptance of the new cosmological paradigm. We pioneered the use of supercomputer simulations to follow the transformation of the near- uniform primordial soup to a cosmic web of galaxies, clusters and larger structures. We developed state-of- the-art techniques, now routinely used by groups around the world, to calculate how the mixture of dark and ordinary matter evolves throughout cosmic history Contents to produce the majestic structures that we see in the universe around us. We are a driving force in the de- 2 The Ogden Centre sign and analysis of the largest galaxy surveys which we have used to test our theories. 3 Research at the ICC

4-5 Research Highlights

6 Astro Snapshots

7 Research Impact

8 New Projects

9 Why do Galaxies come in different shapes and sizes?

9 Research Training

The Cosmology Machine, which is part of the DiRAC Facility jointly funded by STFC, the Large Facilities Capital Fund of BIS, and Durham University, 10-12 Bringing Light to a dark Uni- is one of the most powerful supercomputers in Europe. As Professor Frenk verse - published in Frontiers explains: “The ICC is the UK base for Virgo Consortium, a network involving around 25 researchers in Britain, Germany, Canada, Japan and the USA. 13 From Fundamental Particles to We are looking for answers to how the universe began and continues to Galaxies and the Universe develop. We test theories about the formation of objects, from primordial hydrogen gas clouds to great clusters of galaxies, and use the supercom- 14-15 Our Cosmic Origins: Building puter to run simulations of how the universe would have developed accord- the Milky Way ing to a particular theory. If the computer universe we create resembles the observed universe around us, this indicates the theory is well-founded.’’

ICC 3 ICC research has been featured on BBC televi- sion, such as Horizon (left), Newsnight and the Sky at Night, on the Discovery Channel and on BBC Radio Four’s Today Programme.

Research highlights

4 ICC ICC 5

Research Impact

ICC 7 New ProjectsDark Energy Unveiling dark energy: mapping the cosmos with Pan-STARRS

The discovery that the expansion of the Universe is speeding up rather than slowing down was the biggest surprise in cosmology during the 1990s. Understanding the dark energy responsible for this accelerating expansion is arguably the biggest problem in the whole of physics.

Durham has taken a major step towards cracking the nature of dark energy by joining a new international effort to map the Universe. Pan- STARRS — the Panoramic Survey Telescope and Rapid Response Sys- tem — is a unique instrument designed to carry out the most ambitious astronomical survey to date. Built by the University of Hawaii (UoH), with the largest CCD camera (right) ever used in a civilian project, Pan- STARRS will produce the largest cosmic map ever made.

UoH assembled a consortium of 4 additional members to run the project. From about a dozen bids, UoH selected the Max Planck Society (Heidelberg and Munich), Harvard, Johns Hopkins University and a UK team made up of the Universities of Durham, Queen's Belfast and Edin- burgh. Being selected in preference to prestigious institutions in the USA is a huge scoop for the UK.

The Pan-STARRS-1 (PS1) telescope (left) saw first light in June 2006. The survey will run for 3.5 years from 2010. Pan-STARRS site dedication 2006 The PS1 galaxy catalogue will revolutionize cosmology and studies of the solar system and near-earth objects. High precision measurements of the galaxy distribution will constrain the nature of the dynamically dominant dark energy component of the Universe. PS1 will set the bench- mark in this area for the next decade. Durham is coordinating the PS1 team efforts to analyse the large-scale structure of the Universe and to produce mock catalogues for the PS1 Consor- tium. Durham’s participation is supported by the Ogden trust and Cartoon by Dick Adair, Honolulu Advertiser October 10 2002. Durham University. Ultimate map of the Universe: The Euclid Mission Euclid Durham astronomers are par- Simulations run at the ticipating in a new European ICC have provided Space Agency mission, vital input into the called Euclid. Euclid is a design of the Euclid merger of two experiments mission. Euclid was to map the Universe in recently adopted as exquisite detail: one was an M-class mission an imaging survey de- by the European signed to map the dark Space Agency, with matter distribution through a scheduled launch weak lensing distortion of date of 2019. The faint background galaxies map of the cosmos and the other was a spectro- produced by Euclid will scopic survey to produce a 3D help us to understand the map of the galaxy distribution. nature of dark energy.

8 ICC Why do galaxies come in different shapes? and sizes?.. ? ? ?

Why are some galaxies actively forming stars whereas others are not? What is the connection between galaxies and dark matter? What is the impact of dark energy on the large scale structure of the Universe? ICC researchers test their ideas about the formation of cosmic structures using computer simulations. These simulations cover enormous ranges of scales in length and time and run on some of the world's biggest and fastest supercomputers, like the Cosmology Machine at Durham. The above images show one example of a series of calculations being carried out with the aim of improv- ing our understanding of the physics of galaxy formation. Research Training

Durham has an established re- between particle physics and cosmology. The cord of training young research- ICC will also coordinate a new FP7 Initial Train- ers from all over the year. Typi- ing Network, CosmoComp, with partners in cally we recruit around 10 stu- Europe, China and Latin America. dents a year to begin PhD The ICC is the coordinating node of the Cos- courses. moComp initial training network, which is com- Around half of these are funded by prised of ten of the leading research centres in studentships from the Science and cosmological simulations across the world. Technology Facilities Council. The international standing of the group means that we have attracted students from as far a field as Chile, China and South Korea in the past few years. Durham was the co-ordinating institution of an EC funded project to provide training to young researchers at the key European centres of computational cosmology. The ALFA-II network, LE- NAC, carried out 150 training visits in a little over 3 years, with around 30 of these trips being to Durham. The LENAC project was selected as an example of “best practice” with the ALFA-II programme. A group of LENAC visitors from Argen- tina and Chile is pictured right. The Ogden Centre was awarded a Marie Cu- rie Host Fellowship for Early Stage Training. This project, which fostered research links between the ICC and IPPP, funded 5 PhD positions to work on research into topics at the interface, Five of our alfa LENAC visiting students

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From Fundamental Particles to Galaxies and the Universe

This project, originally funded by PPARC, aims to develop a public outreach programme in astronomy and particle physics in the North of England. The primary target is 11-16 year old school children and their teachers, and the focus is on exploring the origin of the Universe, the properties of fundamental particles and the nature of the dark matter, building upon the work of the Ogden Centre for Fundamental Physics at Durham.

The project is driven by a full-time co-ordinator, Dr. Pete Ed- wards. Since the project began in 2002, over 20,000 school pu- pils from all age groups have been engaged in the latest break- throughs in our attempts to understand the Universe. Activities include “Masterclasses’’ in astronomy and particle physics, NAGTY Summer Schools as well as numerous school visits. Dr. Edwards was chosen to deliver the Institute of Physics Schools Lecture Series in 2006, presenting “Gravity, Gas and Stardust” to over 12,000 students across the country in 47 venues.

The ICC is a vigorous contributor to the outreach program, being selected to take part in the Royal Society’s prestigious Summer Science Exhibition in 2002, 2005 and 2009. A 3D movie made for the 2005 event, “Cosmic Cookery”, made in col- laboration with Nic Holliman’s 3D Visualization Laboratory at Durham, won first Prize in the 2006 vizNet Visualization Showcase. The 2009 exhibit is described overleaf. In January 2010 Cosmic Origins beat off competition from Disney to win an international 3D movie prize.

ICC 13 Our Cosmic building There is no bigger question in science than our cosmic origins. We all want to know why are we here, what is special about our world, what will happen in the future. Cosmology seeks answers to these questions through the known laws of physics. The Milky Way is our cosmic habitat. This vast collection of gas, stars and dust is about 50,000 light-years in size, hosts a super-massive black hole at its centre and is embedded in a huge clump of dark matter.

Researchers at the ICC and Durham University have created the movie “Cosmic Origins” which takes us on a journey looking out into the cosmos around us. At a distance of 400,000 kilometres, the moon is the furthest man has travelled. Apollo 11 took 4 days to get there, but a beam of light can complete the journey in little over a second. Eight light minutes away lies the Sun.

The Sun formed four and a half billion years ago from a cloud of gas and dust. Pulled together by gravity, the left- over debris collected over time to form the Earth, the moon, the rest of the solar system ... and us. The Milky Way is making new stars like the Sun in places like the Orion nebula, one thousand light years away.

At the heart of the Milky Way, 20 thousand light years away, the stars are moving at close to the speed of light! But, why are they moving like this? The gravity of an invisible black hole, 4 million times more massive than our Sun, holds them in orbit, just like the Sun holds the solar system together. Imagine if we could remove the gravity of the black hole -- the stars would then fly away.

What will be the fate of the Milky Way? Our nearest large neighbour, Andromeda, lies two and a half million light years away, and is hurtling towards us at a speed of sev- eral hundred kilometers per second. In a few billion years, the two will become entwined in a cosmic dance. Gravity, the architect of our Universe, will rip stars and dark matter out of each galaxy. As the Milky Way and Andromeda fuse, a new galaxy will emerge. Cosmic evolution will continue to forge ahead.

14 ICC Origins the Milky Way

Recent ground-breaking calculations by the international Virgo Consortium have un- covered the formation history of the Milky Way in unprecedented detail. The simulations followed the growth of the Milky Way’s dark matter halo over more than 13 billion years of cosmic history. The simulation shows that at an early stage, the Milky Way’s dark matter halo was divided up into hundreds of thousands of fragments. The halo built up as these fragments merged, brought together by the force of gravity. This is the biggest calculation to date of the formation of the Milky Way. The simulation used over one billion particles to represent the dark matter. The calculation was carried out on a supercomputer at the Leibnitz Computing Centre in Germany and took more than 3.5 million hours to complete. Over 1000 processors worked on the calculation non-stop for nearly five months.

We can simulate the formation of galaxies using everyday physics here on earth. This “snow-shaker” helps to visualise the processes that affect the evolution of galaxies. Polystyrene balls represent the gas. When the balls are in the air they have a lot of energy. As they lose energy, gravity pulls them back down to the bottom of the dome. This is the cooling of the hot gas. Jets of air are periodically blasted through vents, propelling the balls upwards, against gravity. These blasts of air correspond to “feedback processes” that heat up the gas.

Computer simulations are the tool of choice for the cosmologist who is try- ing to find out how galaxies were made. The computer can be in- structed to follow a set of rules which encapsulate our understanding of the processes that shape galaxies.

To illustrate this we modelled the movement of fluid inside a lava lamp. The figure on the right is a photo of the real lave lamp while the picture on the left is a screen shot from our simulation. The physical processes involved such as buoyancy, pressure differences and turbulence are com- plicated. This is where we rely on a computer.

In a similar way if we want to simulate real galaxies we need to correctly de- scribe the gas in galaxies. We com- pare simulations with real galaxies and from this we can learn if we have got the ingredients of the model right.

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The Institute for Computational Cosmology Ogden Centre for Fundamental Physics South Road, Durham, DH1 3LE. UK http://www.icc.dur.ac.uk Tel: +44 (0)191 334 3635 Fax: +44 (0)191 334 3645