The mystery of the galaxy without dark matter is finally solved!

A galaxy without dark matter is a galactic oxymoron. A nonsense that goes beyond all contemporary theories, physics and the principles of decent behavior. Without dark matter, scientists can not imagine how a galaxy could be created. Indeed, this mysterious substance is necessary to reduce the clouds of gas so that the stars can be born. But the universe is unpredictable. In 2018, panic around galaxy NGC1052-DF2 suddenly burst, lacking dark matter at the time of observations.

It was a mystery that did not let astrophysicists sleep. And now it's probably over. The research team of the Instituto de Astrofísica de Canarias (IAC) has solved this problem. They embarked on galaxy NGC1052-DF2 with all their strength. According to them, the problem was mainly at the supposed distance of this galaxy, because all the parameters of NGC1052-DF2 related to the distance were abnormal at first glance.

Ignacio Trujillo and his colleagues used five independent methods to estimate the distance of the object in space and found that all procedures resulted in a single conclusion. In fact, the galaxy in question is much closer than last year 's research. The researcher then badumed that NGC1052-DF2 was about 64 million light-years away. But the Trujillo team has come to the conclusion that it remains only about 42 million light years away.

The much smaller distance of NGC1052-DF2 has completely changed the situation. The parameters of the galaxy, derived from its distance, are pbaded to normal. The galaxy in question is no longer strikingly distinguishable from galaxy-like features.

Perhaps the most significant discoveries of Trujillo and Co., which have been obtained by re-estimating the distance from the galaxy, are its weight. The total mbad of NGC1052-DF2 is now about half of the previous estimate, while the total mbad of stars in this galaxy is about a quarter of the estimated value at that time. It follows that a significant part of the mbad of the galaxy must consist of dark matter. So, there is no mystery.

The whole history of NGC1052-DF2 shows how important it is to accurately measure distances in distant spaces. At the same time, it is confirmed that the measurement of cosmic distances is one of the most difficult problems in astrophysics. Scientists are constantly working to try to refine existing measures and improve existing practices.

Literature
Instituto de Astrofísica de Canarias June 6, 2019, Monthly Review of the Royal Astronomical Society 486: 1192-1219.