Active galaxies host supermassive black holes in their cores. The intense gravity of the black hole creates a turbulent cauldron of extreme physics. These galaxies, such as NGC 5548 in this study, are too far away for the plasma fireworks to be directly imaged. Therefore astronomers use X-ray and ultraviolet spectroscopy to infer what is happening near the black hole. The new twist is the detection of a clumpy stream of gas that has swept in front of the black hole, blocking its radiation. This deep look into a black hole's environment yields clues to the behavior of active galaxies.
They may be little, but they pack a big star-forming punch. Hubble astronomers have found that dwarf galaxies in the young universe were responsible for an "early wave" of star formation not long after the big bang. The galaxies churned out stars at a furiously fast rate, far above the "normal" star formation expected of galaxies. Understanding the link between a galaxy's mass and its star-forming activity helps to assemble a consistent picture of events in the early universe.
The COSMOS facility, which is located in the Stephen Hawking Centre for Theoretical Cosmology (CTC) at the University, is dedicated to research in cosmology, astrophysics and particle physics. It was switched on in 2012.
To date, the facility has been used to simulate the dynamics of the early Universe and for pipelines analysing the statistics of Planck satellite maps of the cosmic microwave sky. The COSMOS supercomputer was the first very large (over 10 terabyte) single-image shared-memory system to incorporate Intel Xeon Phi coprocessors, which are behind the most power-efficient computers in the world.
Intel Parallel Computing Centres (IPCC) are universities, institutions, and labs that are leaders in their field. The centres are focusing on modernising applications to increase parallelism and scalability through optimisations that leverage cores, caches, threads, and vector capabilities of microprocessors and coprocessors.
As an IPCC, the COSMOS research facility will receive enhanced Intel support from its applications and engineering teams, as well as early access to future Intel Xeon Phi and other Intel products aimed at high-performance computing. IPCC status will allow COSMOS to better focus on delivering computing advances to the scientific community it serves and also highlight the efforts Intel has put into advancing high-performance computing.
When operating at peak performance, the COSMOS Supercomputer can perform 38.6 trillion calculations per second (TFLOPS), and is based on SGI UV2000 systems with 1856 cores of Intel Xeon processors E5-2600, 14.8 TB RAM and 31 Intel® Xeon PhiTM coprocessors.
The research centre has already developed Xeon Phi for use in Planck Satellite analysis of the cosmic microwave sky and for simulations of the very early Universe. These capabilities will become even more important in the near future pending the arrival of new generations of Intel Xeon Phi coprocessors and associated technologies.
“I am very pleased that the COSMOS supercomputer centre has been selected among the vanguard of Intel Parallel Computing Centres worldwide,” said Professor Stephen Hawking, founder of the COSMOS Consortium. “These are exciting times for cosmology as we use COSMOS to directly test our mathematical theories against the latest observational data. Intel’s new technology and this additional support will accelerate our scientific research.”
“Building on COSMOS success to date with Intel’s Many Integrated Core-based technology, our new IPCC status will ensure we remain at the forefront of those exploiting many-core architectures for cosmological research,” said COSMOS director, Professor Paul Shellard. “With the SGI UV2 built around Intel Xeon processors E5-2600 family and Intel Xeon Phi processors, we have a flexible HPC platform on which we can explore Xeon Phi acceleration using distributed, offload and shared-memory programming models. Intel support will ensure fast code development timescales using MICs, enhancing COSMOS competitiveness and discovery potential.”
“Intel Parallel Computing Centres are collaborations to modernise key applications to unlock performance gains that come through parallelism, enabling the way for the next leap in discovery.
We are delighted to be working with the COSMOS team in this endeavour as they strive to understand the origins of the universe,” said Stephan Gillich, Director Technical Computing, Intel EMEA.
COSMOS is part of the Distributed Research utilising Advanced Computing (DiRAC) facility, funded by the Science & Technology Facilities Council and the Department of Business Innovation and Skills.
Cambridge’s COSMOS supercomputer, the largest shared-memory computer in Europe, has been named by computer giant Intel as one of its Parallel Computing Centres, building on a long-standing collaboration between Intel and the University of Cambridge.computingsupercomputerSpotlight on innovationPaul ShellardStephen HawkingIntelCentre for Theoretical CosmologyDepartment of Applied Mathematics and Theoretical PhysicsSchool of the Physical SciencesThese are exciting times for cosmology as we use COSMOS to directly test our mathematical theories against the latest observational dataStephen HawkingUniversity of CambridgeCOSMOS
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Precision measurement of the Newtonian gravitational constant using cold atoms
Nature 510, 7506 (2014). doi:10.1038/nature13433
Authors: G. Rosi, F. Sorrentino, L. Cacciapuoti, M. Prevedelli & G. M. Tino
About 300 experiments have tried to determine the value of the Newtonian gravitational constant, G, so far, but large discrepancies in the results have made it impossible to know its value precisely. The weakness of the gravitational interaction and the impossibility of shielding the effects of gravity make it very difficult to measure G while keeping systematic effects under control. Most previous experiments performed were based on the torsion pendulum or torsion balance scheme as in the experiment by Cavendish in 1798, and in all cases macroscopic masses were used. Here we report the precise determination of G using laser-cooled atoms and quantum interferometry. We obtain the value G = 6.67191(99) × 10−11 m3 kg−1 s−2 with a relative uncertainty of 150 parts per million (the combined standard uncertainty is given in parentheses). Our value differs by 1.5 combined standard deviations from the current recommended value of the Committee on Data for Science and Technology. A conceptually different experiment such as ours helps to identify the systematic errors that have proved elusive in previous experiments, thus improving the confidence in the value of G. There is no definitive relationship between G and the other fundamental constants, and there is no theoretical prediction for its value, against which to test experimental results. Improving the precision with which we know G has not only a pure metrological interest, but is also important because of the key role that G has in theories of gravitation, cosmology, particle physics and astrophysics and in geophysical models.
Fundamental constants: A cool way to measure big G
Nature 510, 7506 (2014). doi:10.1038/nature13507
Authors: Stephan Schlamminger
Published results of the gravitational constant, a measure of the strength of gravity, have failed to converge. An approach that uses cold atoms provides a new data point in the quest to determine this fundamental constant. See Letterp.518