Astronomy: Dark matter map

Science News
from research organizations

Astronomy: Dark matter mapped

Date:
March 1, 2017
Source:
Yale University
Summary:
One of the highest-resolution maps of dark matter ever created has now been revealed, offering a detailed case for the existence of cold dark matter -- sluggish particles that comprise the bulk of matter in the universe.
Share:
FULL STORY

This is a 3-D visualization of reconstructed dark matter clump distributions in a distant galaxy cluster, obtained from the Hubble Space Telescope Frontier Fields data. The unseen matter in this map is comprised of a smooth heap of dark matter on which clumps form.
Credit: Yale University
A Yale-led team has produced one of the highest-resolution maps of dark matter ever created, offering a detailed case for the existence of cold dark matter -- sluggish particles that comprise the bulk of matter in the universe.
The dark matter map is derived from Hubble Space Telescope Frontier Fields data of a trio of galaxy clusters that act as cosmic magnifying glasses to peer into older, more distant parts of the universe, a phenomenon known as gravitational lensing.
Yale astrophysicist Priyamvada Natarajan led an international team of researchers that analyzed the Hubble images. "With the data of these three lensing clusters we have successfully mapped the granularity of dark matter within the clusters in exquisite detail," Natarajan said. "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."
Scientists believe dark matter -- theorized, unseen particles that neither reflect nor absorb light, but are able to exert gravity -- may comprise 80% of the matter in the universe. Dark matter may explain the very nature of how galaxies form and how the universe is structured. Experiments at Yale and elsewhere are attempting 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.
Dark matter particles are thought to provide the unseen mass that is responsible for gravitational lensing, by bending light from distant galaxies. This light bending produces systematic distortions in the shapes of galaxies viewed through the lens. Natarajan's group decoded the distortions 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. This agreement with the standard model is notable given that all of the evidence for dark matter thus far is indirect, said the researchers.
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. A study detailing the findings appeared Feb. 28 in the journal Monthly Notices of the Royal Astronomical Society.

Story Source:
Materials provided by Yale University. Original written by Jim Shelton. Note: Content may be edited for style and length.
 

Highest-resolution 3D maps of dark matter created

Deccan Chronicle - ‎7 hours ago‎
..

Highest-resolution 3D maps of dark matter created

PTI
Published Mar 2, 2017, 2:00 pm IST
Updated Mar 2, 2017, 2:04 pm IST
Scientist have created one of the highest-resolution 3D maps of dark matter ever.
The dark matter map is derived from Hubble Space Telescope Frontier Fields data of a trio of galaxy clusters that act as cosmic magnifying glasses to peer into older, more distant parts of the universe, a phenomenon known as gravitational lensing. (Representational image)
 The dark matter map is derived from Hubble Space Telescope Frontier Fields data of a trio of galaxy clusters that act as cosmic magnifying glasses to peer into older, more distant parts of the universe, a phenomenon known as gravitational lensing. (Representational image)
Scientists, including one of Indian origin, have created one of the highest-resolution 3D maps of dark matter ever, offering detailed evidence for the existence of the elusive particles believed to make up about 80 per cent of the universe.
The dark matter map is derived from Hubble Space Telescope Frontier Fields data of a trio of galaxy clusters that act as cosmic magnifying glasses to peer into older, more distant parts of the universe, a phenomenon 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.
Scientists believe 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 explain the very nature of how galaxies form and how the universe is structured. Experiments at Yale and elsewhere are attempting 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.
Dark matter particles are thought to provide the unseen mass that is responsible for gravitational lensing, by bending light from distant galaxies. This light bending produces systematic distortions in the shapes of galaxies viewed through the lens. Natarajan's group decoded the distortions 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. 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.

Soon, 'magic' DNA computer that grows itself

The Indian Express - ‎5 hours ago‎
In a first, scientists have designed a new, super-fast form of a 'magic' computer made of DNA molecules that grows as it computes and can outperform all standard systems in solving important practical problems

Soon, ‘magic’ DNA computer that grows itself

"But our new computer doesn't need to choose, for it can replicate itself and follow both paths at the same time, thus finding the answer faster"

By: PTI | London | Published:March 2, 2017 4:16 pm
computer, magic computer, DNA computer, computer grows itself, self growing computer, growing computer, universal turing machine, UTM, DNA, DNA computing, science, gadgets, science news “But our new computer doesn’t need to choose, for it can replicate itself and follow both paths at the same time, thus finding the answer faster” In a first, scientists have designed a new, super-fast form of a ‘magic’ computer made of DNA molecules that grows as it computes and can outperform all standard systems in solving important practical problems. Researchers from The University of Manchester in the UK showed the feasibility of engineering a universal Turing machine (UTM) – a computer that can be programmed to compute anything any other device can process. Electronic computers are a form of UTM, but no quantum UTM has yet been built.
The theoretical properties of such a computing machine, including its exponential boost in speed over electronic and quantum computers, have been well understood for many years – but the breakthrough demonstrates that it is actually possible to physically create a UTM using DNA molecules.
Watch all our videos from Express Technology
“Imagine a computer is searching a maze and comes to a choice point, one path leading left, the other right. Electronic computers need to choose which path to follow first,” said Ross D King, from The University of Manchester. “But our new computer doesn’t need to choose, for it can replicate itself and follow both paths at the same time, thus finding the answer faster,” said King.
“This ‘magical’ property is possible because the computer’s processors are made of DNA rather than silicon chips. All electronic computers have a fixed number of chips,” he said. “Our computer’s ability to grow as it computes makes it faster than any other form of computer, and enables the solution of many computational problems previously considered impossible,” he added.
“Quantum computers are an exciting other form of computer, and they can also follow both paths in a maze, but only if the maze has certain symmetries, which greatly limits their use,” King said. “As DNA molecules are very small a desktop computer could potentially utilise more processors than all the electronic computers in the world combined – and therefore outperform the world’s current fastest supercomputer, while consuming a tiny fraction of its energy,” he said.
DNA computing is the performing of computations using biological molecules rather than traditional silicon chips. In DNA computing, information is represented using the four-character genetic alphabet – A (adenine), G (guanine), C (cytosine) and T (thymine) – rather than the binary alphabet, which is a series of 1s and 0s used by traditional computers. The research appears in the Journal of the Royal Society Interface.
..