The known universe contains trillion of galaxies with billions of stars in it. Looking at the big picture, the galaxies in universe are connected to each other by an invisible web of dark matter. Due to some clever use of gravitational lensing these threads of dark matter are now captured for the first time. A team of astronomers at the University of Waterloo in Canada has seen the unseeable using the space-bending effects of dark-matter to create a visual of their dark features by combining the catalogues of galaxy groups that act as lenses with catalogues of data on the light-sources behind them.
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| S. Epps & M. Hudson / University of Waterloo |
Interesting thing is that what we observe through telescope only makes the five percent of observable universe. Other 68 percent of it exists, is some sort of energy that pushes space apart at ever faster speeds. Since so little else is known about this, the cause is referred to as 'dark energy'.
We only know the effect of dark matter not its cause and it makes almost 27 percent of the observable universe.
Dark matter is different. It makes up about 27 percent of the observable Universe; and like dark energy, we can see an effect without knowing much about what seems to be causing it. Clumps of dark matter sit silently, making a bit of a dent in the surrounding fabric of the Universe but not responding to anything else. That effect is basically gravity.
As most materials that have mass also seem to either emit or absorb electromagnetic radiation. So far we are not able to calculate the exact mass there should be to account for the movements and positions of stars and galaxies. Through this we are able to analyze that old bright matter form clumps while more prevalent dark matter forms holes around the glowing gas and stars.
That also means galaxies tend to settle along these threads, forming interconnected super-clusters that stretch out in maps not just of space, but of time itself. Knowing dark matter lies between visible galaxies on the cosmic web is one thing – actually seeing it is something else. The curves and dimples that produces with the drifts of light caused effects of gravity.
The threads of dark matter appear to be strongest between bunches of galaxies less than 40 million light-years apart. Adding this resolution to existing maps could reveal a few more enticing details about this mysterious form of matter and would tell us how Universe evolved. The astronomers were able to use slight variations to build a relatively detailed map of the bridges of otherwise invisible dark matter connecting them, by combining various images of 23,000 pairs of galaxies about 4.5 billion light-years away.
Epps said: "By using this technique, we're not only able to see that these dark matter filaments in the universe exist, we're able to see the extent to which these filaments connect galaxies together."
Researcher Mike Hudson said: "For decades, researchers have been predicting the existence of dark-matter filaments between galaxies that act like a web-like superstructure connecting galaxies together. This image moves us beyond predictions to something we can see and measure."
It'll just make us picture the Universe as a cosmic ball of sugar.
This research was published in Monthly Notices of the RoyalAstronomical Society.
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