UNITED STATES (VOP TODAY NEWS) – Scientists have discovered an unusually transparent galaxy, roughly the size of the Milky Way. It can become a source of unique information for astrophysicists.
The object, code-named NGC1052-DF2, looks like it does not have dark matter.
If this is confirmed, then this galaxy may turn out to be the first of its kind – consisting only of baryon (visible) matter.
Modern physical theory postulates that most of the mass of the universe is in dark matter. At the same time, the existence of it can be judged only by indirect evidence, such as interaction with baryonic matter.
The article was published in the journal Nature.
The authors of the study did not initially seek to find a galaxy in which there is no dark matter. They studied the large ultradiffusion galaxies.
They have the same dimensions as the spiral galaxies with which science is well known, but there are many fewer stars in them.
When Professor Peter van Dokkum, the head of the study, first noticed the object NGC1052-DF2, he “peered at the image for a long time and was simply perplexed … it looked like a ghostly glow in space,” he recalls.
In this galaxy there are very few stars, but many of them are grouped in unusually bright “bunches”. After studying them, scientists found that the total mass of their stars was the entire mass of this galaxy.
Which meant that the mass of dark matter in it was simply missing.
“Dark matter galaxies are about five times larger than normal galaxies,” explains Dr. Michel Collins, a physicist at the University of Surrey (UK), who did not participate in this study.
“The further we move in the direction from the center of the galaxy, the more we meet dark matter and fewer stars themselves.” The halo of dark matter in the galaxy is longer than the stars themselves, “she added.
They can not without each other
Since dark matter has used a greater weight than usual, scientists believe that the first holds the gas required for the formation of galaxies.
“That is, this galaxy should have been formed in a different way: perhaps as a result of reactions within a gas that flows towards or out of a larger galaxy,” explains the astrophysicist at the University of North Carolina, Dr. Catherine Mack.
“This applies not only to galaxies,” explains Dokkum, “the whole universe is clinging to dark matter.”
The most surprising quality of the found galaxy, according to Mack, is that her example can prove the reality of dark matter, which was predicted theoretically, but empirically, scientists were not observed.
An alternative explanation of what is called dark matter could be that it is some unexplained effect of the gravity of visible matter. However, then this effect would be observed in the new galaxy.
“That is, all this can only make sense if the dark matter – present or absent in the galaxy – exists separately from ordinary matter,” added Mack.
A team of scientists is also preparing to publish another article, in which bright clusters of stars will be considered more closely. It can explain to us the riddle of the galaxy NGC1052-DF2.
However, before reviewing the theory of dark matter, more research should be done on similar objects in our universe.
“One must always be cautious with statements about a find,” notes Dokkum, “Of course, this galaxy is the best candidate for the title of baryon galaxy.”
Dr. Collins does not hurry to say that this galaxy does not have a halo of dark matter at all.
She believes that in the universe there can be other galaxies with unusual characteristics for modern scientific knowledge. But first you need to make sure of the accuracy of the technologies by which they can be studied.
“Next to us there are several galaxies that have similar characteristics, but are even more blurred,” she explained.
Dr. Richard Massey, a physicist at the University of Durham, agrees.
“I am really impressed by the work of my colleagues, their conclusions reinforce the view that it is necessary to closely monitor such objects for a longer time, but for now I would not make any deep conclusions about the nature of dark matter,” he told the BBC, si.