Astronomers have discovered a galaxy in which there is no dark matter

An “impossible” galaxy without dark matter. As you can see, the impossible - possibly
Dark matter , despite the fact that they write and talk about it everywhere and everywhere - is just a hypothetical form of matter. According to one hypothesis, now generally accepted, it does not emit electromagnetic radiation and does not directly interact with it. As a result, dark matter is difficult to directly detect by methods that are used by man. However, there are methods of indirect detection - for example, by gravitational influence on nearby objects. Clarification of the nature of dark matter, according to astronomers, allows us to solve the problem of hidden mass, which, in particular, lies in the abnormally high speed of rotation of the outer regions of galaxies.

Dark matter exerts a gravitational influence, sometimes very strong, on the behavior of stars, their clusters and other objects. This is exactly how scientists discover this mysterious form of matter (unless, of course, this is really dark matter). At the moment, in almost all discovered and studied galaxies, signs of the existence of dark matter have been found. But recently, astronomers have discovered a galaxy in which, apparently, there is no this form of matter. Why? No one knows.

The galaxy was discovered by chance , largely due to the fact that it did not behave as it should if it were "normal". Found it with Dragonfly Array , a host of small telescopes designed to detect faint objects that emit a minimum of light. While observing a group of galaxies NGC 1052, it was this group of telescopes that "spotted" an object that had previously been seen in this part of the sky.

“We noticed it, because there is a pretty big difference in how it appeared before Dragonfly Array and its display in the Sloan Digital Sky Survey data,” the authors of the study on the “bright galaxy” said. The object was a diffuse element with some structures inside.

Detailed observation of it with the Hubble and the 10-meter Keck telescope made it possible to see some details of the image of the object, called NGC1052 – DF2. As it turned out, it is a galaxy belonging to the recently discovered class of ultra-diffuse galaxies. This type of galaxy is like a bubble through which you can see everything behind it.

Such galaxies have been discovered repeatedly, although infrequently in some galactic clusters. Some of them interacted with neighboring galaxies, giving them their own stars and gas-dust structures. But dark matter remained with them, so it can be said that some diffuse galaxies received “enrichment” with dark matter.

In order to find out what is happening with the object NGC1052 – DF2, the researchers used the Keck telescope to obtain images of structures inside this galaxy. This work allowed, in particular, to calculate the mass of the galaxy.

It turned out that the mass of NGC1052 – DF2 is extremely low for, in fact, the galaxy - only 10 to 8 degrees of the mass of the Sun. Using data on the luminosity of the galaxy, scientists found that there are about the same number of stars in it - 10 to 8 degrees. That is, in fact, all the stars and the mass of the galaxy are “in sight”. Usually galaxies are heavier than the aggregate masses of their stars, which allows us to judge the presence of dark matter. But not in the case of NGC1052 – DF2.

According to astronomers, all this can only say one thing - that NGC1052 – DF2 is either very poor in dark matter, or there is no such mysterious substance in the galaxy at all. The most interesting thing is that most models of the Universe and its objects, built by scientists, provide for the presence of dark matter. And a galaxy that is deprived of it requires a special relationship to itself — calculations must be done anew, taking into account the absence of an “additional weight”.

How did the galaxy form without the participation of dark matter? One of the assumptions - NGC1052 – DF2 was formed from matter ejected by quasars. Maybe it was originally a gas cloud the size of a galaxy and a high concentration of gas, which allowed us to start the formation of stars and, in fact, the galaxy itself.

Now scientists are busy studying the structural features of the galaxy, trying to understand how NGC1052 – DF2 differs from “normal” galaxies, including the one in which we live.