The curvature of spacetime around the massive mass has provided the most detailed measurements of the cosmic distribution of dark matter. Using gravitational lensing, a team led by cosmologist Kaiki Taro Inoue of Kindai University in Japan has mapped the mysterious form of matter at the smallest scale we have ever seen, with a resolution of just 30,000 light-years.

This may sound huge, but it’s even more impressive when you consider that the Milky Way is roughly 100,000 light-years across. Researchers have managed to map things we can’t see at a scale of over 7.5 billion light-years, less than a third of our galaxy. This is great.

The analysis was based on random alignments of space objects known as gravitational lensing. Space-time curves around massive objects in a way similar to the way it appears under your body when you sit on a trampoline. If you roll balls on a trampoline mat, they will not move in a straight line, but in a curved line following a round surface.

Something similar happens when light flowing through space encounters distorted space-time around a large object such as a galaxy or galaxy cluster. So if, say, there is a distant galaxy behind one of these objects, the light from the more distant galaxy will be distorted and strengthened as it travels through distorted space-time.

One of the reasons this is great is that scientists can study these distant galaxies in much more detail than they could without the lens. But the way the light distorts and smears can also reveal the distribution of gravity in the foreground lens.

This turns out to be a great way to find where dark matter is hiding. We don’t know what dark matter is; Since it does not emit light, we cannot detect it directly. We know that there is an invisible mass in the universe that creates extreme gravity. We can detect the effect of this gravitational force and thus track where the mass is hiding.

It still doesn’t tell us what dark matter is, but locating it could help us understand how it works. In the case of gravitational lensing, when you subtract all normal matter (i.e. galaxies) from the mass distribution decoded from the distorted light of the background object, what remains is dark matter.

That’s what Inoue and his colleagues did with a gravitational lensing galaxy called MG J0414+0534, which is so distant that its light takes about 11.3 billion years to reach us. A little closer, the foreground lenticular galaxy distorted the light into four images.

The positions of these split images cannot be fully explained by the lensing effect of the visible parts of the foreground galaxy. So, using the powerful Atacama Large Millimeter/Submillimeter Array and a new analysis technique, researchers extracted the influence of visible parts of the lensing galaxy on bent light from MG J0414+0534 to produce a more detailed map of the lensing dark matter. .

This resulting map supports the theory that there are many dark matter clusters inside galaxies and in the space between galaxies, as predicted by the cold dark matter theory. This confirms for the first time that this theory remains consistent at this scale, which is smaller than galaxies.

Researchers say this is a powerful new tool to help understand dark matter. The inability to determine its distribution on scales smaller than galaxies has hindered efforts to constrain its properties. Being able to do this will help scientists narrow down the identity of the mysterious mass present everywhere. Source