Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dark matter haloes favour Frisbee over Rugby

20.04.2007
A new study of dark matter haloes indicates that they are shaped like Frisbees, not Rugby-balls as has been suggested. Aaron Robotham, of the University of Bristol, will be presenting the results at the Royal Astronomical Society’s National Astronomy Meeting in Preston on Friday 20th April.

A group from the University of Bristol and the Cerro-Tololo Inter-American Observatory in Chile has developed a sophisticated computer model to work out the three-dimensional shape of the dark matter using the positions of groups of galaxies which are embedded the haloes. Dark matter haloes are studded with galaxies but being discrete objects the true halo shape may not be apparent by just simply measuring their distribution.

The new model is able to fill in the gaps with an unprecedented degree of accuracy, presenting a truer picture of the shape of the ellipsoids. The results for the corrected data show that the dark matter haloes are non-spherical but flattened out like a Frisbee, most preferentially in the smallest groups of galaxies. When the group had analysed the raw data the ellipsoids had appeared to be shaped like a Rugby ball or American Football, which was also the shape preferred by previous studies.

“Our findings are that dark matter haloes are Frisbee shaped, that means that dark matter is not simply spherically distributed, and indicates that filamentary structure is not a strong influence on the shape of the group halo- prolate shapes would be strongly favoured in this case” said Robotham. “The apparent oblate shapes that are allowed after correction mirrors that seen for the Local Group and has often been suggested in computer models.”

The shape of dark matter haloes gives us information about how the early universe formed and how the haloes have evolved. According to cosmological theory, soon after the Big Bang cold dark matter formed the universe’s first large-scale structures, which then collapsed under their own weight to form vast halos. The gravitational pull of these haloes sucked in normal matter and provided a focus for the formation of galaxies. How the shape of these halos have evolved over time is a subject of much debate, complicated by a vast number of factors that mean extremely large samples are required in order to extract meaningful statistics.

The scientists used the 2-degree Field Percolation Inferred Galaxy Groups (2PIGG) catalogue, the largest survey of galaxy groups that is publicly available. The group’s findings have been submitted for publication in the Astrophysical Journal.

Anita Heward | alfa
Further information:
http://www.nam2007.uclan.ac.uk/info.php
http://www.ras.org.uk//index.php?option=com_content&task=view&id=1181

More articles from Physics and Astronomy:

nachricht A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>