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Primeur weekly 2014-05-19

The Cloud

IBM named no. 1 preferred provider of IaaS Cloud by enterprises ...

IBM closes acquisition of Silverpop ...

Introducing IBM Cloud Manager with OpenStack ...

South Korean Agency turns to IBM mainframe Cloud to better engage and serve South Korean citizens ...

Bright Computing announces an integrated OpenStack solution at the OpenStack Summit in Atlanta ...

Desktop Grids

Mass number-crunching may help crack Alzheimer's disease code ...

EuroFlash

PRACE Annual Report 2013 now available ...

DKRZ chooses Bull for its first Petaflops-scale supercomputer and for co-operation on climate research in Germany, as part of an initial contract worth 26 million euro ...

Barcelona hosts 500 experts in advanced computing ...

The turbulent birth of stars in galactic collisions ...

Using nature as a model for low-friction bearings ...

USFlash

Carnegie Mellon will test Internet architecture in vehicular network and for on-line video ...

IBM unveils software defined storage technology for era of Big Data ...

PSC and Hopkins computer model helps Benin vaccinate more kids at lower cost ...

University of Maryland launches new supercomputer to expand high-performance computing for research ...

HP reinvents data back-up with predictive, social-enabled data protection ...

IBM Research sets new record for storing massive amounts of Big Data ...

IBM reveals new companies developing Watson-powered apps ...

Pawsey Supercomputing Centre second stage details released ...

Fast and curious: Electrons hurtle into the interior of a new class of quantum materials ...

HP helps customers speed design, deployment of applications and services ...

IBM Research discovers new class of industrial polymers ...

National Institutes of Health funding to help expand data storage capacity at UC Riverside ...

EMC inaugurates Big Data R&D centre in Brazil ...

Raritan unveils fast and intelligent rack power transfer switch at Cisco Live ...

The turbulent birth of stars in galactic collisions

15 May 2014 Paris - Using very high-resolution numerical simulations, astrophysicists at the CEA and CNRS, led by Florent Renaud, have, for the very first time, achieved a detailed analysis of the effects of turbulence generated when two galaxies collide. These numerical simulations, in which the disordered motions of the gas contained in galaxies are seen at extremely small-scale resolutions, at last explain a phenomenon that astrophysicists have observed but which they have been unable to understand until now: that of "starbursts" of star formation when galaxies collide. A process of compressive turbulence helps to explain such starbursts, and why some galaxies form more stars than others. These results are published inMonthly Notices of the Royal Astronomical Society Letters, May 2014.

Stars are formed when the gas contained in certain regions of a galaxy becomes dense enough to collapse in on itself - usually due to gravity. When two galaxies collide, a "starburst" of star formation is generally observed, for reasons hitherto unknown.

A galactic collision increases the disordered motion of the gas, and the vortices of turbulence thus generated should prevent the gas from condensing due to gravity. One would therefore expect that this turbulence would slow down, and even prevent star formation, whereas in fact the opposite is observed.

The very high-resolution simulations demonstrate that, in reality, the collision has changed the very nature of the turbulence at a very small scale: the vortex effect is replaced by a gas compressive mode. Contrary to all expectation, turbulence thus contributes to the collapse of the gas by compressing it. Thus, when two galaxies clash into one another, it is this compressive turbulence effect that triggers an excess of dense gas and, thereby, a starburst of star formation, in regions that cover a large volume of the galaxies, and not only in their central regions. This process now appears to play a crucial role in triggering star formation.

To obtain these results, the researchers used two of the most powerful supercomputers available through PRACE, the European research infrastructure, including GENCI's Curie supercomputer and LRZ's SuperMUC supercomputers to model an isolated galaxy, like the Milky Way, and a collision between two galaxies such as that which gave birth to the pair of galaxies known as the "Antennae Galaxies".

Research modelling these two well-known galaxies has resulted in the development of the most realistic simulations to date of the objects observed.

These new simulations have achieved a level of precision never seen before, making it possible to resolve structures with a mass 1,000 times smaller than ever before. This has enabled the astrophysicists to track the evolution of the galaxies over hundreds of thousands of light-years, and to explore a mere fraction of a light-year in detail. Thanks to this decisive advantage, new physical effects emerged, revealing the complex nature of turbulence.

“The type of research done by Florent Renaud and his team demands very large computing capacities; capacities so large that only PRACE can provide them in Europe,” says Kenneth Ruud, Chair of the PRACE Scientific Steering Committee. "These results therefore show that Europe is at the forefront of both ground-breaking science as well as world-class HPC."

Our knowledge of galaxies is based on the light emitted by stars within them, especially in the case of young stars. Stars form when the gas in a galaxy condenses. This makes them emit particularly intense ultraviolet and infrared light. When two galaxies collide, a great many stars form very rapidly, and astronomers then observe a peak in the emission of this type of light, known as a "starburst".

The paper titled "Starbursts triggered by inter-galactic tides and interstellar compressive turbulence", is written by Florent Renaud, Frédéric Bournaud, Katarina Kraljic & Pierre-Alain Duc. It appears inMonthly Notices of the Royal Astronomical Society Letters, Oxford University Press, May 2014, doi: 10.1093/mnrasl/slu050.
Source: PRACE

Back to Table of contents

Primeur weekly 2014-05-19

The Cloud

IBM named no. 1 preferred provider of IaaS Cloud by enterprises ...

IBM closes acquisition of Silverpop ...

Introducing IBM Cloud Manager with OpenStack ...

South Korean Agency turns to IBM mainframe Cloud to better engage and serve South Korean citizens ...

Bright Computing announces an integrated OpenStack solution at the OpenStack Summit in Atlanta ...

Desktop Grids

Mass number-crunching may help crack Alzheimer's disease code ...

EuroFlash

PRACE Annual Report 2013 now available ...

DKRZ chooses Bull for its first Petaflops-scale supercomputer and for co-operation on climate research in Germany, as part of an initial contract worth 26 million euro ...

Barcelona hosts 500 experts in advanced computing ...

The turbulent birth of stars in galactic collisions ...

Using nature as a model for low-friction bearings ...

USFlash

Carnegie Mellon will test Internet architecture in vehicular network and for on-line video ...

IBM unveils software defined storage technology for era of Big Data ...

PSC and Hopkins computer model helps Benin vaccinate more kids at lower cost ...

University of Maryland launches new supercomputer to expand high-performance computing for research ...

HP reinvents data back-up with predictive, social-enabled data protection ...

IBM Research sets new record for storing massive amounts of Big Data ...

IBM reveals new companies developing Watson-powered apps ...

Pawsey Supercomputing Centre second stage details released ...

Fast and curious: Electrons hurtle into the interior of a new class of quantum materials ...

HP helps customers speed design, deployment of applications and services ...

IBM Research discovers new class of industrial polymers ...

National Institutes of Health funding to help expand data storage capacity at UC Riverside ...

EMC inaugurates Big Data R&D centre in Brazil ...

Raritan unveils fast and intelligent rack power transfer switch at Cisco Live ...