Both dark matter and dark energy are a mystery, hence their names. We have not been able to see them directly, only through indirect observations. In fact, this same week an investigation was published in the scientific journal Astrophysical Journal in which a dark matter map showing how its filaments link galaxies together. It is not a direct observation, but it brings us closer to understanding how dark matter is distributed in the universe.
There are various experiments and investigations looking expectantly for direct indications that dark matter exists. But for the moment we have not found her. That does not mean that indirect observations are not one of the keys to understanding more and better what dark matter is.
An example is this new map, but there are many others. In this case, it has been developed using «machine learning», they indicate in Phys.org. This’ could allow studies on the nature of dark matter, as well as the history and future of our local universe«, They add.
Map of dark matter within the local universe, using a model to infer its location due to its gravitational influence on galaxies (black dots). Credit: HONG ET. TO THE
The researchers thought that dark matter could constitute the skeleton of the universe and this map, in which they are observed filaments that bind galaxies, seems to match this. But as we said, we cannot see dark matter. So to develop this map, the researchers had to infer where the dark matter is “based on its gravitational influence on other objects in the universe, such as galaxies.”
Observing distant galaxies can help us understand how dark matter is distributed. The researchers developed a computer model to help us know where dark matter may be today. Remember that, when looking at distant galaxies, we are seeing the past. We know how it was distributed in the past and now we need to predict where it is in the present. And that’s where this model and the observation of other closer ones come in, such as the Cosmicflow-3 catalog of galaxies.
It has not been easy for researchers to come up with a model that can predict this. But now we have a map in which, in addition, they have found that there are filamentous structures both inside and outside galaxies as they connect them together, like a skeleton that shapes the universe. The next step is to better investigate all of these structures.
“Having a local map of the cosmic web opens a new chapter in cosmological study,” explains Donghui Jeong, associate professor of astronomy and astrophysics at Penn State and author of the study. “We can study how the distribution of dark matter relates to other emission data, which will help us to understand its nature. And we can directly study these filamentous structures, these hidden bridges between galaxies.
The team wants to add new galaxies to this first map to make it more accurate and to have more information about this structure that seems to tie the universe together.
What is dark matter?
Dark matter produces gravitational effects that we can observe
The main theories now focus on the fact that they are massive particles that do not interact with other atoms. Hence, for the moment, we can’t see it. But, as we said, we can intuit it indirectly. That is, due to the gravitational effects that dark matter produces in galaxies. And is that some galaxies do not rotate in the way they should because of the mass that we calculate they have. So we assume that there is a mass that we cannot see and that explains its behavior. That was the solution he provided Vera rubin when he discovered that the data did not add up.
We now know that dark matter could make up about 80% of the universe. And we have not been able to directly observe or detect it. This is one of the reasons why in 2022, if everything goes according to plan, the Euclid mission from the European Space Agency (ESA) and that could give us new information on both dark matter and dark energy, another very interesting phenomenon.
We still don’t know everything about the universe. In fact, a large part of it is unknown to us, and this is shown to us by both the lack of direct detection of dark matter and that of dark energy. One day, hopefully, we will know more about these two phenomena. But for now, researchers will have to keep stargazing.