May 24, 2022


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New Dark Matter Map Shows The Bridges Between The Milky Way And Nearby Galaxies

A new map of darkish subject designed making use of artificial intelligence reveals hidden filaments of the invisible stuff bridging galaxies.

The map focuses on the area universe — the community bordering the Milky Way. Inspite of currently being near by, the area universe is difficult to map since it’s chock entire of complex buildings made of visible issue, stated Donghui Jeong, an astrophysicist at Pennsylvania Condition University and the lead author of the new investigation. 


“We have to reverse engineer to know wherever dim subject is by wanting at galaxies,” Jeong told Dwell Science.

Related: The 11 most important unanswered concerns about darkish subject

Dark matter is a mysterious, invisible material that interacts with visible make a difference via gravity.

Some researchers theorize that this invisible make any difference might consist of weakly interacting large particles, or WIMPs, which would be very big (for subatomic particles, in any case) and electromagnetically neutral, so that they would not interact with everything on the electromagnetic spectrum, this kind of as light.

An additional idea with some likely evidence to back it up is that dark make any difference might consist of ultralight particles known as axions.

Regardless of what dim make any difference is, its effects are detectable in the gravitational forces permeating the universe.

Mapping out an invisible gravitational drive is just not uncomplicated, although.

Commonly, scientists do it by functioning significant computer simulations, beginning with a model of the early universe and quickly-forwarding by means of billions of yrs of growth and evolution of noticeable make any difference, filling in the gravitational blanks to figure out exactly where dark subject was and the place it ought to be right now. This needs significant computing electric power and major amounts of time, Jeong explained.


This new research requires a diverse strategy. The scientists very first skilled a device-understanding software on countless numbers of computer simulations of noticeable matter and darkish make any difference in the regional universe.

Device finding out is a technique that is especially adept at selecting out styles from big datasets. The model universes in the analyze arrived from a sophisticated set of simulations known as Illustris-TNG.

Immediately after testing the equipment-learning algorithm’s instruction on a next set of Illustris-TNG universe simulations for accuracy, the scientists utilized it to actual-environment knowledge.

They used the Cosmicflows-3 galaxy catalog, which retains info on the distribution and motion of the visible make a difference within 200 megaparsecs, or 6.5 billion light-years, of the Milky Way. That spot consists of a lot more than 17,000 galaxies.

(Hong et. al., Astrophysical Journal, 2021)

Over: These density maps – each and every a cross-area in different proportions –reproduce recognized, distinguished options of the universe (crimson) and also reveal more compact filamentary functions (yellow) that act as concealed bridges involving galaxies. The X denotes the Milky Way galaxy and arrows denote the movement of the regional universe because of to gravity.

The final result was a new map of dark make any difference in the local universe and its associations to seen make a difference.


In a promising discovering, the device-mastering algorithm reproduced significantly of what was already recognised or suspected about the Milky Way’s community from cosmological simulations.

But it also instructed new features, together with long filaments of dark make a difference that join galaxies all-around the Milky Way to it and to just one one more. 

This is essential for comprehending how galaxies will move about time, Jeong mentioned.

For case in point, the Milky Way and the Andromeda galaxies are envisioned to crash into every other in about 4.5 billion decades.

Comprehending area dim matter’s job in that collision could support tackle extra exactly how and when that merger – and others – will come about.

“Now that we know the distribution of dim matter we can determine extra properly the acceleration that will go the galaxies all around us,” Jeong stated. 

The exploration appeared May perhaps 26 in the Astrophysical Journal.

Linked content material:

6 approaches the hunt for dim issue has altered

The 11 largest unanswered queries about darkish subject

The 18 biggest unsolved mysteries in physics 

This short article was initially printed by Stay Science. Read through the first write-up listed here.