Scientists solve cosmological puzzle

Nov 29, 2007
Scientists solve cosmological puzzle
It is a picture of a dwarf galaxy forming one billion years after the Big Bang. The background image shows the large-scale cosmic context (the panel is approximately 100,000 light years across); the inset shows the central 2,000 light years of the dwarf galaxy where powerful feedback from newly born star clusters drives bulk motions in the gas. Stars are shown in yellow; colours from violet to blue to green to white correspond to gas of increasing density. Credit: S. Mashchenko, J. Wadsley, and H. M. P. Couchman

Researchers using supercomputer simulations have exposed a very violent and critical relationship between interstellar gas and dark matter when galaxies are born – one that has been largely ignored by the current model of how the universe evolved.

The findings, published today in Science, solve a longstanding problem of the widely accepted model – Cold Dark Matter cosmology – which suggests there is much more dark matter in the central regions of galaxies than actual scientific observations suggest.

“This standard model has been hugely successful on the largest of scales—those above a few million light-years—but suffers from several persistent difficulties in predicting the internal properties of galaxies,” says Sergey Mashchenko, research associate in the Department of Physics & Astronomy at McMaster University. “One of the most troublesome issues concerns the mysterious dark matter that dominates the mass of most galaxies.”

Supercomputer cosmological simulations prove that indeed, this problem can be resolved. Researchers modeled the formation of a dwarf galaxy to illustrate the very violent processes galaxies suffer at their births, a process in which dense gas clouds in the galaxy form massive stars, which, at the ends of their lives, blow up as supernovae.

“These huge explosions push the interstellar gas clouds back and forth in the centre of the galaxy,” says Mashchenko, the lead author of the study. “Our high-resolution model did extremely accurate simulations, showing that this ‘sloshing’ effect – similar to water in a bathtub— kicks most of the dark matter out of the centre of the galaxy.”

Cosmologists have largely discounted the role interstellar gas has played in the formation of galaxies and this new research, says Mashchenko, will force scientists to think in new terms and could lead to a better understanding of dark matter.

The simulations reported in the research paper were carried out on the Shared Hierarchical Academic Research Computing Network (SHARCNET).

Source: McMaster University

Explore further: A new generation of storage—ring

add to favorites email to friend print save as pdf

Related Stories

Universe may face a darker future

20 hours ago

New research offers a novel insight into the nature of dark matter and dark energy and what the future of our Universe might be.

Astronomy & Astrophysics: Planck 2013 results

Oct 29, 2014

Astronomy & Astrophysics is publishing a special feature of 31 articles describing the data gathered by Planck over 15 months of observations and released by ESA and the Planck Collaboration in March 2013. ...

Topological defects in the fabric of space and time

Oct 10, 2014

A cosmic string is a very long (possibly as long as the diameter of the visible universe), very thin (less than the width of a proton) high-density object formed during the early moments of the big bang. ...

On the front lines of the Higgs boson search

Oct 10, 2014

Finding the Higgs boson at CERN involved an exciting chain of events and sharing it with the wider public through the media was also a journey of discovery, Prof. Jon Butterworth told an audience at the IOP's ...

Recommended for you

A new generation of storage—ring

16 hours ago

A bright synchrotron source that emits over a wide part of the electromagnetic spectrum from the infrared to hard X-rays is currently being built in Lund, Sweden. The MAX IV facility presents a range of technical ...

High-intensity sound waves may aid regenerative medicine

Oct 30, 2014

Researchers at the University of Washington have developed a way to use sound to create cellular scaffolding for tissue engineering, a unique approach that could help overcome one of regenerative medicine's ...

Formula could shed light on global climate change

Oct 30, 2014

Wright State University researchers have discovered a formula that accurately predicts the rate at which soil develops from the surface to the underlying rock, a breakthrough that could answer questions about ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

seanpu
not rated yet Nov 30, 2007
gas gas gas, all they see is gas! Where's all the plasma gone?
quantum_flux
not rated yet Nov 30, 2007
plasma and gas are sometimes used interchangeably in astronomy. This is exciting.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.