School of Physics and Astronomy

Craters made by asteroid impacts may be the best place to look for signs of life on other planets, a study suggests.

Tiny organisms have been discovered thriving deep underneath a site in the US where an asteroid crashed some 35 million years ago.

Scientists believe that the organisms are evidence that such craters provide refuge for microbes, sheltering them from the effects of the changing seasons and events such as global warming or ice ages.

The study suggests that crater sites on Mars may also be hiding life, and that drilling beneath them could lead to evidence of similar life forms.

“The deeply fractured areas around impact craters can provide a safe haven in which microbes can flourish for long periods of time. Our findings suggest that the subsurface of craters on Mars might be a promising place to search for evidence of life.” Professor Charles Cockell, of the University of Edinburgh’s School of Physics and Astronomy

Researchers from the University of Edinburgh drilled almost 2km below one of the largest asteroid impact craters on Earth, in Chesapeake, US. Samples from below ground showed that microbes are unevenly spread throughout the rock, suggesting that the environment is continuing to settle 35 million years after impact.

Scientists say that heat from the impact of an asteroid collision would kill everything at the surface, but fractures to rocks deep below would enable water and nutrients to flow in and support life. Some organisms grow by absorbing elements such as iron from rock.

The research was published in the journal Astrobiology.

The collision of two 4 TeV proton beams at the LHC’s four interaction points signalled the start of this year's physics data-taking by the LHC experiments. The collision energy of 8 TeV set a new world record, and considerably increases the discovery potential  of the LHC.

Although the increase in collision energy is relatively modest, it translates to an increased discovery potential that can be several times higher for certain hypothetical particles. Some such particles, for example those predicted by supersymmetry, would be produced much more copiously at the higher energy. Supersymmetry is a theory in particle physics that goes beyond the current Standard Model, and could account for the dark matter of the Universe.

"Its very exciting. When one is so close to the LHC machine, it is great to see the ramp up going so well." Prof. Peter Clarke, Institute for Particle and Nuclear Physics

Standard Model Higgs particles, if they exist, will also be produced more copiously at 8 TeV than at 7 TeV, but background processes that mimic the Higgs signal will also increase. That means that the full year’s running will still be necessary to convert the tantalising hints seen in 2011 into a discovery, or to rule out the Standard Model Higgs particle altogether.

"The LHC and its experiments are well positioned to have a third year of data-taking at higher energy and at increased collision rates. Members of the Edinburgh ATLAS and LHCb groups were in the pit when the beams were switched on and we will be in the midst of the exciting physics results to come from the 2012 data." Prof. Franz Muheim, Head of the Institute for Particle and Nuclear Physics

“The increase in energy is all about maximising the discovery potential of the LHC,” said CERN Research Director Sergio Bertolucci. “And in that respect, 2012 looks set to be a vintage year for particle physics.”

"We are very excited. During this year we hope to collect enough data for a first real answer on the Higgs Boson's existence. It may still take several years to discover or exclude it, particularly at low mass, and beyond doubt." Phil Clark, Institute for Particle and Nuclear Physics

The LHC is now scheduled to run until the end of 2012, when it will go into its first long shutdown in preparation for running at an energy of 6.5 TeV per beam as of late 2014, with the ultimate goal of ramping up to the full design energy of 7 TeV.
 

Watch a video about the LHC restart. 

Dr Kristel Torokoff, a lecturer in the School of Physics & Astronomy, has been awarded the Simon Van Heyningen Award for Teaching in Science and Engineering.

One student who nominated Kristel described her as: "Most reliable and dedicated teacher you can encounter. Offers her free time to help and support students that have troubles in particular courses, organizing tutorial on Sunday/Saturdays or during lunch break. Helpful towards everyone, even students that are not in her courses." 

"This prize reflects just what bright and hard working students we have in Physics. It's a pleasure to be working with them." Dr Kristel Torokoff

Arthur Trew, Head of the School, said, "The University takes these awards very seriously so to have won is a great achievement for Kristel personally and for the School more generally. To have won it in the difficult area of teaching mathematics is doubly impressive."

Edinburgh University Students’ Association announced the winners at an Oscar-style ceremony in Teviot Row House, hosted by the new University Rector, Peter McColl. Mike Williamson, EUSA VP Academic Affairs, said: "Students have shown their appreciation for good teaching once again. The judging panel was struck by the number of heart-warming comments from students who wanted to thank their lecturers, tutors and support staff. Hopefully the awards will continue to be a success for many years to come."

EUSA's Teaching Awards are in their fourth year, and the scheme is fully supported by the University. Each year has seen thousands of nominations by students of their lecturers, tutors, courses and departments. This year students were also able to nominate teaching support staff, which brought recognition for departmental secretaries, students who support other students' learning through peer-support schemes, and staff who support disabled students in their learning, among others.

Obtaining metallic hydrogen, the Holy Grail of high pressure science, has been a long-standing problem in Condensed Matter Science. The high pressure behaviour of hydrogen has major implications for the interiors of the Jovian planets (the gas giants: Jupiter, Saturn, Neptune and Uranus). High pressure experiments have been driven over the past 70 years not just by the desire to convert the most abundant element in the universe metallic, but through predictions of exotic properties the material may exhibit, such as superfluidity and high temperature superconductivity.

Through new technological breakthroughs in diamond anvil cell experiments, a team of researchers at the Centre for Science at Extreme Conditions at the University of Edinburgh and Geophysical Laboratory, Washington DC have not only set a pressure record for the compression of hydrogen at room temperature but discovered a new phase - one of only four known phases - at conditions that exceed 2.2 million times atmospheric pressure.

"This interesting new phase is exemplary of how pressure can introduce complexity in an element otherwise thought as simple and provides a continuous, elegant pathway to the metallization of hydrogen. These are exciting times in high pressure hydrogen research and the discovery of a new phase will without doubt stimulate further studies and drive experiments in obtaining the elusive metallic state." PhD student Ross Howie, the first author on the Physical Review Letter where the discovery is reported.

The new phase consists of 'honeycomb' layers between which unbound molecules intersperse. Such a structure is highly unusual, exhibiting a mixture of both atomic and molecular properties. Predictions (Pickard and Needs, 2007) suggest this phase will evolve if further compressed, electrically conducting along the honeycomb layers much like graphite. Despite reaching 3.2 million times atmospheric pressure at room temperature, the metallic state is still to be attained. Nonetheless, as it was previously thought that hydrogen would become conducting in either the pure atomic or pure molecular state, this study is crucial in the understanding of the nature of metallic hydrogen.

Powerful supercomputers have shed light on the behaviour of key sub-atomic particles, in a development that could help explain why there is almost no anti-matter in the Universe.

An international collaboration of scientists, including physicists from the Universities of Edinburgh and Southampton, has reported a landmark calculation of the decay of an elementary particle called a kaon, using breakthrough techniques on some of the world’s fastest supercomputers.

The calculation took 54 million processor hours on the IBM BlueGene/P supercomputer at the Argonne Leadership Class Facility (ALCF) at Argonne National Laboratory in the US.

The new research, reported in the March 30 issue of Physical Review Letters, represents an important milestone in understanding kaon decays - which are a fundamental process in physics. It is also inspiring the development of a new generation of supercomputers that will allow the next step in this research.

“It has taken several decades of theoretical developments and the arrival of very powerful supercomputers to enable physicists to control the interactions of the quarks and gluons, the constituents of the elementary particles, with sufficient precision to explore the limits of the standard model and to test new theories,” says Chris Sachrajda, Professor of Physics at the University of Southampton, one of the members of the research team publishing the new findings.

“The present calculation focuses on the fundamental question of how we arrived at a universe composed almost exclusively of matter with virtually no antimatter, but the theoretical and computational techniques of Lattice Quantum Chromodynamics (see below) will also be central to unraveling the underlying framework behind the discoveries anticipated at the Large Hadron Collider at CERN.”

The next generation of IBM BlueGene/Q machines is expected to have 10 to 20 times the performance of the current machines:

“With this dramatic boost in computing power we can get a more accurate and complete version of the present calculation, and other important details will come within reach, " said Dr Peter Boyle, University of Edinburgh. "This is a nice synergy between science and the computer — the science pushing computer developments and the advanced computers pushing science forward, to the benefit of the science community and also the commercial world.” 

The process by which a kaon decays into two lighter particles known as pions was explored in a 1964 Nobel Prize-winning experiment. This revealed the first experimental evidence of a phenomenon known as charge-parity (CP) violation — a lack of symmetry between particles and their corresponding antiparticles that may explain why the Universe is made of matter, and not antimatter.

When kaons decay into lighter pions, the constituent sub-particles known as quarks undergo changes brought about by weak forces that operate at such a small scale. As the quarks move away, they exchange gluons – particles that cause the quarks to bind into the pions.

The computations are performed using the techniques of lattice quantum chromodyamics (QCD: the theory that describes fundamental quark-gluon interactions), in which the decay is input into a computer as a finite grid of space-time points. The problem of calculating the decay rate can be reduced to a statistical method, called the Monte Carlo method. The present calculation extends the range of lattice QCD calculations to a new class of process, weak decays with two strongly interacting particles in the final state.

Whilst the calculation reported here has determined fundamental quantities necessary for an understanding of the matter-antimatter asymmetry, it also marks the beginning of the next phase of the collaboration’s work. This will involve improving the precision of the computations and extending the range of physical quantities for which the effects of the strong nuclear force can be quantified.

Comparing experimental measurements of rare processes with the predictions of the standard model is a powerful tool to search for signatures of new physics and in discriminating between proposed theories. Lattice QCD will be a central tool in these studies, but in most cases even more computing power is required.

Dr Peter Boyle, University of Edinburgh, who co-authored the paper, said: “Fortunately the next generation of IBM supercomputers is being installed over the next few months in many research centres around the world, including the Blue-Gene/Q at Edinburgh, part of the DiRAC (Distributed Research utilising Advanced Computing) facility of which both the Edinburgh and Southampton groups are members, as well as at ALCF, the KEK laboratory in Japan, the Brookhaven National Lab and the Riken Brookhaven Research Center (RBRC) in the US.” 

The project was carried out by physicists from the Brookhaven National Laboratory, Columbia University, the University of Connecticut, the University of Edinburgh, the Max-Planck-Institut für Physik, RBRC, the University of Southampton ​and Washington University.

The calculations were performed under the U.S. Department of Energy’s (DOE) Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program on the Intrepid BlueGene/P supercomputer in ALCF at Argonne National Laboratory and on the Ds Cluster at Fermi National Laboratory, computer resources of the U.S. QCD Collaboration. Part of the analysis was performed on the Iridis Cluster at the University of Southampton and the DiRAC Cluster at the University of Edinburgh.

The research was supported by DOE’s Office of Science, the U.K’s Science and Technology Facilities Council, the University of Southampton, and the RIKEN Laboratory in Japan.

Astronomers have today released a picture containing more than one billion stars in our Milky Way galaxy. It combines data from two near-infrared1 telescopes – the UK Infrared Telescope (UKIRT) in Hawaii and the VISTA telescope in Chile - and is the result of a decade-long collaboration by astronomers at the University of Edinburgh and the University of Cambridge to process, archive and publish the prodigious quantities of sky survey data generated by these two telescopes.

Dr Phil Lucas from the University of Hertfordshire leads the UKIRT study of the Milky Way, and co-leads the VISTA study. He said: “The combined data on over a billion stars represent a scientific legacy that will be exploited for decades in many different ways. They provide a three-dimensional view of the structure of our spiral galaxy, the Milky Way, while also mapping several hundred nebulae where stars are being born. The VISTA data, in particular, is breaking new ground by showing how several hundred million stars vary in brightness over time."

The full image contains 150 billion pixels, and the detail it contains is only revealed by the three zoom levels, centred on G305, a large and complex star-formation region: the innermost zoom covers a tiny fraction of the full image, but still contains more than ten thousand stars.

Presenting the image at the UK-German National Astronomy Meeting in Manchester, Dr Nick Cross of the University of Edinburgh said: “This remarkable image is only one of the many outputs from the VISTA Data Flow System (VDFS) project². VDFS data is being used by astronomers around the world and has led to great discoveries in many fields of astronomy, from the coolest known stars to the most distant quasars.”

“Sky surveys are an increasingly important part of modern astronomy. The data centres supporting them need expertise in both astronomy and the latest information technologies. These two surveys are generating great science now, and will continue to do so for decades ahead, thanks to the careful job we have done in processing, archiving and publishing their data.” Dr Bob Mann, leader of the Edinburgh team 

Professor Jim Emerson of the Queen Mary, University of London, leader of the VDFS development project, added: “Processing and publishing the tens of terabytes of data from modern sky surveys is a demanding and specialised job. By funding expert data centre teams to do that, we left the rest of the community free to do astronomy with the final data products. This is a very cost-effective way to do science.”

Dr Mike Irwin, leader of the Cambridge team explained: “VDFS was conceived as a two-phase project. Initially we handled the UK Infrared Deep Sky Survey (UKIDSS) data from UKIRT, and that prepared us for the much larger data volumes to come from the VISTA sky surveys.”

Professor Steve Warren of Imperial College London is the UKIDSS Survey Scientist. He commented: “The UKIDSS team is being honoured at this conference through receipt of the Royal Astronomical Society Group Award. The great scientific productivity of UKIDSS has relied on the VDFS data products. More than 300 scientific papers have resulted from UKIDSS data. We just wouldn't have got anywhere with the science if we had been trying to process this mountain of data ourselves, individually.”

The UKIDSS survey is drawing to a close, and the focus of VDFS work is now on the sky surveys being undertaken with the VISTA telescope, operated by the European Southern Observatory (ESO) and located in Chile. The VISTA programme³ comprises six surveys targeting different areas of the sky and with different scientific goals:

• VISTA Variables in the Via Lactea (VVV) survey and the VISTA Magellanic Survey (VMC) focus on the stellar populations of the Milky Way galaxy and its immediate neighbours, the Magellanic Clouds, respectively.
• UltraVISTA, the VISTA Kilo-Degree Infrared Galaxy Survey (VIKING) and the VISTA Deep Extragalactic Observations Survey (VIDEO) study external galaxies.
• The VISTA Hemisphere Survey (VHS) includes the whole of the southern sky not covered by the other surveys, and has science goals from both stellar astronomy and extragalactic astrophysics.

VDFS is supporting five of the six surveys - VVV, VMC, VIKING, VIDEO and VHS - and is in the process of making the first public releases of data from them through the VISTA Science Archive (VSA)⁴ in Edinburgh.

Listen to Nick Cross speaking to the BBC about the information that went into making the picture.

N​otes

[1] Near-infrared radiation is invisible to the human eye, but can be felt as heat on the skin in everyday life. It allows astronomers to probe regions of space, such as dust clouds in the Milky Way, that are opaque to visible light, and to identify objects that are too cold or too distant to emit much visible light.

[2] The VISTA Data Flow System (VDFS) project is a collaboration between the Wide-Field Astronomy Unit (WFAU) at the University of Edinburgh and the Cambridge Astronomical Survey Unit (CASU). CASU lead the data processing operations, and WFAU are responsible for the archiving of data products and their publication to the astronomical community.

[3] See VISTA Public Surveys programme for more details.

[4] VISTA Science Archive (VSA). The WFAU team responsible for the design, development and operation of the VSA comprises: Rob Blake, Ross Collins, Nick Cross, Nigel Hambly, Mark Holliman, Andy Lawrence, Bob Mann, Keith Noddle, Mike Read and Eckhard Sutorius.

This research was supported by the Science and Technology Facilities Council (STFC) and its predecessor the Particle Physics and Astronomy Research Council (PPARC).

​All images courtesy of Mike Read (WFAU), UKIDSS/GPS and VVV.

A team of astronomers from the UK, Canada and the Netherlands have commenced a revolutionary new study of cosmic star-formation history, looking back in time to when the Universe was still in its lively and somewhat unruly youth.

The consortium, co-led by University of Edinburgh astrophysicist Professor James Dunlop, is using a brand new camera called SCUBA-2, the most powerful camera ever developed for observing light at "sub-mm" wavelengths (ie light of wavelength 1000 times longer than we can see with our eyes).

SCUBA-2 is mounted on the world's largest sub-mm telescope, the 15-metre James Clerk Maxwell Telescope (JCMT), located atop the 4,300-metre high peak of Mauna Kea in Hawaii. Prof. Dunlop will present the first results from the survey on 27 March at the RAS/AG National Astronomy Meeting in Manchester.

The new project, named the SCUBA-2 Cosmology Legacy Survey will run for 3 years and will provide the clearest view to date of dust-enshrouded star-forming galaxies. These objects are so remote that the light we detect left them billions of years ago, so we see them as they looked in the distant past. With SCUBA-2 astronomers are able to study objects that existed as far back as 13 billion years ago, within the first billion years after the Big Bang.

“We are delighted by these first deep SCUBA-2 images and look forward to more results over the next few years. Edinburgh scientists and engineers worked hard to construct this revolutionary new instrument and, together with our colleagues in Canada and the Netherlands, we’re now seeing the fruits of our efforts. With SCUBA-2 we can study the most violently star-forming galaxies in the young Universe, and slowly but surely start to understand how the primitive cosmos evolved into the universe we live in today.” Prof. James Dunlop, University of Edinburgh

Because stars form inside clouds of gas and dust, much of the ultraviolet light from young galaxies is absorbed by this cosmic dust which is then heated to a few tens of degrees above absolute zero (-273 degrees Celsius). The "warmed" (but still rather “cool”) dust then remits the absorbed energy at far-infrared wavelengths, which is then further redshifted to longer sub-mm wavelengths en-route to the Earth by the expansion of the Universe.

Detecting such emission is a challenge, both because Earth-based telescopes are warm and hence glow at sub-mm wavelengths and because water vapour in the atmosphere both absorbs and emits light in this waveband. To get around the problems of the atmosphere, the latest sub-mm surveys have recently been conducted from space, using the Herschel Space Observatory. However, the relatively small size (3.5-metre diameter) of Herschel means that the images it produces, while covering large areas, are rather fuzzy. Because its primary mirror is 20 times larger in area, the James Clerk Maxwell Telescope, now equipped with SCUBA-2, can provide a much sharper view of the sub-mm sky, especially on those occasions when the sky above the high mountain tops in Hawaii is really dry.

The SCUBA-2 Cosmology Legacy Survey is being targeted at areas on the sky which have already been studied in detail by other telescopes observing at different wavelengths. Of special importance is the Hubble Space Telescope (HST), which is undertaking a major 3-year survey (called CANDELS) of the visible light emission from high-redshift galaxies with its own new camera, Wide Field Camera 3 (WFC3). By combining the JCMT and HST imaging astronomers can gain an unparalleled view of the most massive galaxies which roamed the Universe back in the "golden era" of star formation activity.

The first image presented here is made using the SCUBA-2 camera at a wavelength of 450 microns. Zooming in, it shows seven distinct sub-mm sources that appeared blended together in the poorer-quality Herschel image. The Hubble images then show that the SCUBA-2 sources are massive, clumpy, violently star-forming disc galaxies, seen at a time when the Universe was about a quarter of its present age.

SCUBA-2 was designed and constructed at the Royal Observatory in Edinburgh at the UK Astronomy Technology Centre, before being shipped to the James Clerk Maxwell Telescope (JCMT) in Hawaii.

James Dunlop speaks to the BBC.

A team led by University of Edinburgh astrophysicist Professor James Dunlop has released the most sensitive ever infrared image of a representative region of the distant Universe.

The new image comes from the first year of data taken as part of the five-year UltraVISTA survey. It was made by combining more than six thousand separate exposures equivalent to an exposure time of 55 hours. The image reveals more than 200,000 galaxies, including the most massive galaxies yet seen in the early Universe, objects which formed less than one billion years after the Big Bang.

Commenting on these revolutionary new images, Prof Dunlop said: "Until recently our view back to the first epoch of galaxy formation has been limited to tiny, "pencil-beam" images made with the Hubble Space Telescope. Now VISTA, with its panoramic imaging capability, is providing us with the first view of truly representative regions of the young Universe. This image is just a first taste of what the UltraVISTA survey will ultimately provide."

"UK astronomers can be very proud of this achievement. Until the launch of the James Webb Space Telescope, UltraVISTA gives us the best view we will have of the large-scale distribution of the earliest galaxies." Prof John Peacock, Head of the University of Edinburgh's Institute for Astronomy.

The UltraVISTA survey area co-incides with the location of the largest optical image taken with the Hubble Space Telescope, termed the COSMOS survey. The combination of the existing Hubble optical imaging and the new VISTA near-infrared data provides a treasure trove for a wide range of astronomical studies. The final UltraVISTA image is expected to reveal objects 5-10 times fainter still, enabling the study of galaxy evolution over essentially all of cosmic time.

The image combines exposures taken through five different near-infrared filters using the European Southern Observatory's new VISTA telescope, located at the Paranal Observatory in Chile. The design and construction of VISTA was also led from Edinburgh, at the UK Astronomy Technology Centre at the Royal Observatory Edinburgh (ROE). The synergy of academic and technological expertise makes the ROE one of the worlds leading astronomical institutions.

Our MSc in High Performance Computing (HPC) is a well established programme that provides an excellent grounding in HPC technologies and their practical application.

The Virtual Open Days are live sessions in chat rooms hosted by the MSc in HPC programme director, Dr David Henty. Presentations from staff are followed by a questions and answer sessions. Topics include an introduction to the MSc in HPC programme, course contents, career opportunities, financial support and other aspects of studying with us.

If you are interested in applying for the MSc in HPC, the Open Days are a good opportunity to:
• Talk to MSc staff
• Discuss career opportunities and financial support
• Meet current students

Upcoming ​MSc in HPC Virtual Open Days

​Thursday 29th March 20​12 13:00 – 14:00 BST

Wednesday 11th April 2012 12:00 – 13:00 BST

Thursday 10th May 2012 12:00 – 13:00 BST

The MSc and HECToR

The ​MSc is taught by experts from EPCC, a supercomputing centre based in the School. EPCC is one of the leading centres of supercomputing expertise in Europe, and it manages an extensive collection of HPC systems including the UK’s national supercomputer HECToR. HECToR has recently been upgraded to more than 90,000 processing cores, making it one of the 20 most powerful supercomputers in the world.

All our MSc students are given accounts on HECToR and they use it extensively for practical exercises and project work. The parallel programming skills taught on the MSc are also essential in exploiting the power of modern multicore processors, computing clusters and graphics processors. The MSc in HPC opens up a wide range of further research and employment opportunities in computational science, software development and HPC support. Many MSc graduates continue to study or work at the University, with 20 students having found subsequent employment at EPCC.

Registration

To book your place, email your name and the session you would like to attend to: msc [at] epcc.ed.ac.uk

The University's first Innovative Learning Week took place in February. During the week, teaching on most courses was replaced by activities designed to explore new ways of learning and to improve our students' university experience.

With the job market increasingly competitive and additional activities important for CVs, Innovative Learning Week gave students an opportunity to participate in events that were experimental, innovative and fun but which also enhanced skills relevant to employability.

The School’s programme provided a mix-and-match menu of talks, projects and workshops from which students could freely choose. There were events suitable for those aiming for leadership roles in society, for future entrepreneurs and for those interested in science communication and teaching. Students intending to take a Physics PhD and those who hope to use subject-specific skills like coding and mathematics could also follow their interests.

As part of the ‘Communicators’ strand, a group of First Year students produced a magazine, The Critical Angle, which reports and comments on the events of the week. The students who worked on the magazine demonstrated excellent teamwork skills in producing a publication with impressively high production values that is well-balanced and informative. Please take a look and magazine [at] ph.ed.ac.uk (subject: Critical%20Angle%20) (let us know) what you think.