Space

What can the collision of galaxies tell about dark matter?

In an infinitely expanding universe inhabitscountless galaxies. Woven from dust and gas, and filled with celestial bodies, these amazing space travelers encounter each other. This is due to gravitational attraction. Inch by inch, light year by light year, the course of the cosmic clock brings the inevitable closer. Massive structures, each of which contains hundreds of billions of stars, mix and ignite. And our galaxy is no exception. Recently, astronomers discovered Antlia 2, a low-density but massive galaxy that, like a ghost, revolves around the Milky Way. Scientists believe that Antlia 2 can help unravel the secrets of dark matter.

This is the collision of three galaxies

How and why do galaxies collide?

In space, gravity controls everything. This is the CEO and leader of every galaxy. The fact is that galaxies are clusters of stars, star systems, clumps of dark matter, clouds of dust and gas interconnected by gravitational attraction. Recently, we wrote that scientists have come closer to understanding what is between the galaxies - most likely it is hydrogen that penetrates the galaxies and leaves them thanks to supernova explosions. And again - without gravity, nowhere.

Scientists: Our galaxy is like the English letter S

However, whatever the hugethe space between the most different galaxies, the force of gravity in one way or another makes it smaller, since the galaxies are pulled towards each other. Our home, the Milky Way galaxy, in a couple of billion years will inevitably collide with the Andromeda galaxy. Their collision will spawn a new galaxy. It is possible that life will be born there too. Let's discuss this in our Telegram chat.

In the photo, the consequences of a collision of two galaxies

Take a close look at this photo: before you are the consequences of a collision of two galaxies. The result of this amazing spectacle will be a new ring-shaped galaxy, which, billions of years later, will again inevitably collide with its closest galactic neighbor. As they say, nothing lasts forever.

The Milky Way Ghost

Last November, astronomers announcedthe discovery of Antalya 2, a galaxy orbiting the Milky Way. The fact is that it is rather difficult to get an idea of ​​the dimensions of our space house from Earth. We know that our galaxy is a flat disk with a convex center. And if you look at it from above, we will see spiral arms of gas and stars. And we will see ripples around the galactic disk. It was the ripples on the outer disk of the Milky Way that puzzled scientists for decades. Thus, the discovery of Antlia 2 will probably help put everything in its place.

During the study, astronomers useddata from the Gaia telescope of the European Space Agency. Scientists have calculated the past flight path of Antlia 2 and discovered that it probably collided with the Milky Way hundreds of millions of years ago. That is how the ripples that we still see today appeared.

The image shows the Antley 2 galaxy next to the Milky Way. A little further to the right is the Large Magellanic Cloud

Scientists used to believe that ripples appeared due tocollisions with the dwarf galaxy Sagittarius. However, a computer simulation confirmed the results - our galaxy is still shaking a bit due to a collision with Antlia 2.

What the discovery of Antlia 2 says about dark matter

The authors of the study believe that the discovery of Antlia2 in the future will help unravel the secrets of dark matter. Recall that the standard model of physics describes only 5% of the substance that exists in the vastness of the universe. But the remaining 95% is hypothetical dark matter - a substance of unknown nature that cannot be detected.

You can read about the amazing facts known to modern science of dark matter on our channel in Yandex.Zen

According to the lead author of the study, SukianiChakrabarti Antlia 2 is a very strange and interesting object, since all the properties of this galaxy are still unknown. It is believed that during the formation of galaxies, the gravity of giant clumps of dark matter is formed into a substance that feeds the birth of stars. Experts believe that the ghost galaxy Antlia 2 could be born from another type of dark matter - faster and more airy. However, do not forget that no one knows the nature of the particles of dark matter.

The density and mass of Antlia 2 is limited - thisthe galaxy is close to the disk at the Milky Way. According to the authors of the study, this means that in the end, scientists will be able to use Antlia 2 as a unique laboratory for studying the nature of dark matter. However, first you have to learn more about this unusual galaxy.