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ESO's XXL galaxy cluster survey could improve our understanding of dark matter

ESO's XXL galaxy cluster surve...
One of the two survey areas as observed by the XMM-Newton telescope – the newly-detected galaxy clusters are circled in red
One of the two survey areas as observed by the XMM-Newton telescope – the newly-detected galaxy clusters are circled in red
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One of the two survey areas as observed by the XMM-Newton telescope – the newly-detected galaxy clusters are circled in red
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One of the two survey areas as observed by the XMM-Newton telescope – the newly-detected galaxy clusters are circled in red
The XMM-Newton X-ray imagery can be seen here superimposed over a ground-based view of the area
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The XMM-Newton X-ray imagery can be seen here superimposed over a ground-based view of the area

An international team of astronomershas used multiple telescopes to study two large patches of sky,searching for the X-ray emissions from distant galaxy clusters. It's hoped that the work will provide insights into thenature of dark matter and dark energy.

The XXL survey, which is one of thelargest ever of its kind, focuses on the most massive gravitationallybound structures in the Universe – galaxy clusters. These massiveobjects house reservoirs of gas with temperatures so high that theyemit X-rays that can be observed by telescopes orbiting Earth.Gaining a better understanding of these clusters is important, asit's believed that they are influenced by the most elusive componentsof the Universe – dark matter and dark energy.

The new survey was conducted by aninternational team of more than 100 astronomers, searching twopatches of sky, each around 100 times the size of the moon. The studyis making use of X-ray observations from the ESA's XMM-Newton orbiting space telescope alongside ground-based data frominstallations such as the ESO's Very Large Telescope (VLT) and New Technology Telescope (NTT), coming together to forma huge collection of data across the electromagnetic spectrum.

The XMM-Newton X-ray imagery can be seen here superimposed over a ground-based view of the area
The XMM-Newton X-ray imagery can be seen here superimposed over a ground-based view of the area

The XMM-Newton telescope was used toidentify the clusters, while the NTT and VLT focused on working outexactly how far away each object is. This two-fold method allowed theastronomers to build a three dimensional view of the clusters, whichin turns allows for the precise measurement and analysis of dark matter and dark energy.

At present, only one fifth of the totalexpected data has been processed, but several interesting discoverieshave already been made. These include the identification of five newgroups of galaxy clusters – each referred to as a supercluster –and evidence to support the notion that the observed galaxy clustersare scaled down versions of those seen in the modern Universe.

The findings also confirmed that thereare a lower number of clusters present in the early Universe thansuggested by predictive models based on observations by ESA's Plancktelescope. While the reason for this is currently unknown, the XXLsurvey team believes that the mystery will be solved once the fullsample data is available, which is expected in 2017.

Source: ESO

3 comments
Bob
Every time I hear the word model in connection with something like this I cringe. Why? Because a model is only accepted if it supports a preconceived idea or can be tested over and over. In this case it can not be tested over and over but will likely be used to support a preconceived theory. It will then be elevated to the level of proof which it is not. I used to work with x-ray spectra and due to a number of interferences, there were several models we used. Which model worked the best? The one that supported our preconceived opinion. Will the models developed from this PROVE dark energy and dark matter? Only if you already believe they exist.
Bob Flint
All of this is moot, the universe as we believe is already (current time here on earth) different from what we observed thousands and millions of light years away. We are trying to glimpse into the past to see the future, but at the vast time scales & distances involved, forget about it. We can't change anything in the fraction of time we have as short lifespan of less than 100 years, even over multiple generations. Believe what you like it matters not light or dark...
mpc755
Dark matter fills the space unoccupied by particles of matter and is displaced by the particles of matter which exist in it and move through it.
The Milky Way's halo is lopsided due to the matter in the Milky Way moving through and displacing the dark matter, analogous to a submarine moving through and displacing the water.
Particles of matter move through and displace the dark matter. A moving particle has an associated wave in the dark matter. There is evidence of dark matter every time a double slit experiment is performed; it's what waves.
http://aetherdisplacement.com