One of the highest-resolution 3D maps of dark matter ever has been created by a team of scientists that includes one of Indian origin. The new 3D map provides detailed evidence for the existence of the elusive particles.
The elusive particles are believed to make up about 80% of the universe and the 3D maps offer detailed proof of their existence.
Hubble Space Telescope Frontier Fields data was used to derive the dark matter map. A trio of galaxy clusters act as cosmic magnifying glasses. Scientists are able to peer into older, more distance parts of the universe using those cosmic magnifying glasses and this phenomenon is known as gravitational lensing.
“With the data of these three lensing clusters we have successfully mapped the granularity of dark matter within the clusters in exquisite detail,” said Priyamvada Natarajan, astrophysicist at the Yale University in the US.
“We have mapped all of the clumps of dark matter that the data permit us to detect, and have produced the most detailed topological map of the dark matter landscape to date,” said Natarajan.According to scientists, dark matter – theorised, unseen particles that neither reflect nor absorb light, but are able to exert gravity - may comprise 80 per cent of the matter in the universe.
Dark matter may hold key to the very nature of how the galaxies were formed and how our universe was structured. Experiments are trying to identify the dark matter particle; the leading candidates include axions and neutralinos.
“While we now have a precise cosmic inventory for the amount of dark matter and how it is distributed in the universe, the particle itself remains elusive,” Natarajan said.
The particles of the dark matter are believed to provide unseen mass leads to gravitational lensing by bending light from distant galaxies.
Systematic distortions in the shapes of galaxies viewed through the lens are produced by the light bending. The distortions were decoded by Natarajan’s group in order to create the new dark matter map.
Significantly, the map closely matches computer simulations of dark matter theoretically predicted by the cold dark matter model; cold dark matter moves slowly compared to the speed of light, while hot dark matter moves faster.
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This agreement with the standard model is notable given that all of the evidence for dark matter thus far is indirect, researchers said.
The high-resolution simulations used in the study, known as the Illustris suite, mimic structure formation in the universe in the context of current accepted theory.
The findings appear in the journal Monthly Notices of the Royal Astronomical Society.
(With inputs from PTI)