Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Universe trapped in its own web

04.04.2006


Astronomers from the University of Nottingham, UK, and the Instituto de Astrofisica de Canarias (Spain), have found the first observational evidence that galaxies are not randomly oriented.



Instead, they are aligned following a characteristic pattern dictated by the large-scale structure of the invisible dark matter that surrounds them.

This discovery confirms one of the fundamental aspects of galaxy formation theory and implies a direct link between the global properties of the Universe and the individual properties of galaxies.


Galaxy formation theories predicted such an effect, but its empirical verification has remained elusive until now. The results of this work were published the 1 April issue of Astrophysical Journal Letters.

Nowadays, matter is not distributed uniformly throughout space but is instead arranged in an intricate “cosmic web” of filaments and walls surrounding bubble-like voids. Regions with high galaxy concentrations are known as galaxy clusters whereas low density regions are termed voids.

This inhomogeneous distribution of matter is called the “Large-scale distribution of the Universe.” When the Universe is considered as whole, this distribution has a similar appearance to a spider’s web or the neural network of the brain. But it was not always like this.

After the Big Bang, when the Universe was much younger, matter was distributed homogeneously. As the Universe was evolving, gravitational pulls began to compress the matter in certain regions of space, forming the large-scale structure that we currently observe.

According to these models and theories a direct consequence of this process is that galaxies should be preferentially oriented perpendicularly to the direction of the linear filaments.

Several observational studies have looked for a preferential spatial orientation (or alignment) of galaxy rotation axes with respect to their surrounding large-scale structures. However, none of them have been successful, due to the difficulties associated with trying to characterise the filaments.

The research conducted by the astrophysical group formed by Ignacio Trujillo (University of Nottingham, UK), Conrado Carretero and Santiago G. Patiri, (both from the Instituto de Astrofisica de Canarias, Spain) has been able to measure this effect, confirming theoretical predictions.

To achieve this goal, they used a new technique based on the analysis of the huge voids that are found in the large-scale structure of the Universe. These voids have been detected by searching for large regions of space depleted of bright galaxies.

In addition, they took advantage of information provided by the two largest sky surveys yet undertaken: the Sloan Digital Sky Survey and the Two Degree Field Survey. These surveys contain positional information for more than half a million galaxies located within a distance of one billion light-years of the Earth.

Other parameters provided by the surveys, such as the position angle and the ellipticity of the objects, were used to estimate the orientation of the disk galaxies.

“We found that there is an excess of disk galaxies that are highly inclined relative to the plane defined by the large-scale structure surrounding them,” explained Dr. Trujillo. “Their rotation axes are mainly oriented in the direction of the filaments.

“Our work provides important confirmation of the tidal torque theory which explains how galaxies have acquired their current spin,” said Trujillo.

“The spin of the galaxies is believed to be intrinsically linked to their morphological shapes. So, this work is a step forward on our understanding of how galaxies have reached their current shapes.”

Dr. Ignacio Trujillo has a research assistant position, funded by PPARC, in the School of Physics and Astronomy at the University of Nottingham.

Peter Bond | alfa
Further information:
http://www.iac.es/gabinete/noticias/2006/univ-gescala/imagen.html

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>