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"It's really uncomfortable. This should not exist; it should not be true, "said Marla Geha, an astronomer at Yale University in 2018, speaking of a strange little galaxy, a small galaxy that does not seem to contain any invisible elements called dark matter. "Yet, if you look at the data, that's the conclusion you're drawn to." Astronomers have long since noticed an invisible elephant in the room – the so-called dark matter, which seems heavier than all visible stars, gas and dust in the room. cosmos by a ratio of 6 to 1.
Since dark matter interacts gravitationally as ordinary matter, it has been speculated that some galaxies may contain a lot of dark matter, but very little visible matter. These "black galaxies", such as Triangulum II, a small galaxy on the edge of our Milky Way, would not be particularly bright, but they would be distinguished by their high gravity.
In contrast, the galaxy NGC 1052 – DF2, a semitransparent light smear located 65 million light-years away in the constellation Cetus, contains about 200 million suns, as well as negligible amounts of gas and phosphorus. dust. And that's all. According to the 2018 study of the astronomer Pieter van Dokkum and Yale, the visible material of the galaxy represents all its mass, a conclusion of common sense which proves profoundly strange.
"The paradox of dark matter" – A tiny galaxy without any proof of its existence
Today, a group of researchers from the Instituto de Astrofísica de Canarias (IAC) has cleared up the mystery of 2018: the existence of NGC 1052 – DF2 "without dark matter".
According to an article published in the Monthly Notices of the Royal Astronomical Society (MNRAS), a group of researchers from the Instituto de Astrofísica de Canarias (IAC) solved this mystery through a comprehensive set of 39 observations of KKS2000.]04 (NGC1052-DF2). 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.
"Ultralight" – "Dark matter exists beyond the standard model"
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 indicated that the galaxy was some 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.
Dark Matter – "came out of an Eon before the Big Bang" (Weekend Feature)
Thanks to these new results, the parameters of the galaxy deduced from its distance have become "normal" and correspond to 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.
The daily galaxy via the Canary Islands Astronomy Institute (IAC)
Image credit: Galaxy lacks dark matter via Arxiv.org
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