Researchers solve the mystery of the galaxy without black matter

A group of researchers from the Instituto de Astrofísica de Canarias (IAC) clarified a mystery of 2018 in the field of extragalactic astrophysics: The supposed existence of a galaxy without dark matter.

Galaxies without dark matter are impossible to understand in the current theory of galaxy formation, because the role of dark matter is fundamental to cause the collapse of gas and form stars. In 2018, a study published in Nature announced the discovery of a galaxy apparently devoid of dark matter.

Now, according to an article published in the Monthly Notices from the Royal Astronomical Society (MNRAS) a group of researchers from the Instituto de Astrofísica de Canarias (IAC) solved this mystery via a very comprehensive set of observations from KKS2000]04 (NGC1052-DF2).

The researchers, perplexed because all the parameters depending on the distance of the galaxy were abnormal, revised the distance indicators available. Using five independent methods to estimate the distance of the object, they discovered that all coincided in one conclusion: the galaxy is much closer to the value presented in the previous search.

The original article published in Nature said that the galaxy is at a distance of about 64 million light years from Earth. However, this new research has revealed that the actual distance is much less important, about 42 million light years away.

Thanks to these new results, the parameters of the galaxy deduced from its distance have become "normal" and correspond to the observed trends traced by galaxies with similar characteristics.

The most relevant data found by the new distance analysis is that the total mass of this galaxy is about half of the previously estimated mass, but the mass of its stars is only about a quarter of the previously estimated mass. . This implies that a significant part of the total mass must consist of dark matter. The results of this work show the fundamental importance of the correct measurement of extragalactic distances. One of the most difficult tasks of astrophysics has always been to measure the distances that separate them from very distant objects.