This galaxy, which is called NGC 1052-DF2, seems to have no dark matter:
A team of astronomers has discovered a unique galaxy, the first of its kind, which seems to contain virtually no dark matter. These experts say that it is an exceptional finding, since it is commonly believed that galaxies contain more dark matter than the ordinary matter that makes up the stars, gas and dust of a galaxy.
In addition, it is generally accepted that galaxies were formed for the first time from concentrations of dark matter that act as "galaxy initiators". Gravitationally, they attract ordinary, or baryonic, matter that eventually settles within the existing cloud of dark matter.
But how was it formed?
"We thought that all galaxies were composed of mixed stars, gas and dark matter, but that dark matter always dominated," says Professor Roberto Abraham, of the University of Toronto, Canada, and co-author of this article, which describes the discovery. "Now it seems that at least there are galaxies with lots of stars and gas and almost no dark matter, it's quite strange," he adds.
When Pieter van Dokkum discovered the galaxy NGC1052-DF2, he was "staring" and was amazed. It was a galaxy about the size of the Milky Way, but unusually transparent. "It was like a ghostly glow in the sky," says Dokkum, a professor at Yale University in the United States.
How to make the invisible visible: this is the most complete map to date of dark matter, one of the great mysteries of the Universe. If this were true, it would be the first time that a galaxy of this type is discovered, composed only of ordinary matter.
Physicists believe that dark matter - which can not be seen because it does not reflect light - is essential to the structure of the Universe as we understand it. The authors of the research published in Nature were not looking for a galaxy free of dark matter, but were looking for ultradiffus galaxies.
This newly discovered "ghost" galaxy also has very few stars, but many of them are grouped in unusually bright clusters.
What is dark matter and what is it for?
Dokkum, for his part, explains that the universe does not consist only of galaxies.
"In reality, the structure of the universe consists of the scaffolding of dark matter and everything else is stuck to it," he says.
Hubble telescope image.
http://www.bbc.com/mundo/noticias-43577683
https://www.frankalmonte.com/2018/03/28/descubren-una-galaxia-fantasmal-sin-apenas-materia-oscura/