An unusual galaxy has become the center of discussion when it comes to dark matter, but the interesting part is that it contains almost no dark matter. According to astronomers, and to the study which the journal Nature recently published, the galaxy called NGC 1052-DF2, or DF2, has about 400 times less dark matter than an object of its size would normally have. It’s interesting that this bizarre galaxy could provide an insight into how galaxies are born. Also, it could help prove that dark matter is indeed a real thing, according to researchers.
According to Pieter van Dokkum, the leader of the study, this fascinating galactic find challenges the idea that galaxies are born thanks to dark matter. For a long time, experts have believed the interaction between dark and normal matter to be the key in the formation of galaxies. However, that might not be the case, and this unusual galaxy proves it. It seems that dark matter is not absolutely necessary for a galaxy to be born. But what actually is this mysterious dark matter? It’s an invisible matter whose presence is only observed through its interaction with normal or baryonic, matter.
An unusual galaxy, devoid of dark matter
Moreover, this unseen matter makes up about 80% of the universe’s entire mass and plays the most important role in galactic evolution. NASA says that the interaction between galaxies and stars within the dark matter have produced the galaxies we are still observing today. So, after carefully analyzing this bizarre galaxy, van Dokkum and his team came to the conclusion that it had a stellar mass of about 200 million solar masses. In this case, the dark matter mass should have been of at least 80,000 million solar masses.
But the surprise came when they realized that it only weighed about 300 million solar masses, far less than expected. Experts are now trying to figure out how did this galaxy actually form, if now thanks to dark matter.
Image source: flickr