Astronomers explain the origin of galaxies without dark matter

Galaxies that seem to have almost no dark matter make it difficult for astronomers to understand its content in

The universe.Dark matter in astronomy and cosmology, as well as in theoretical physics, is a form of matter that does not participate in electromagnetic interaction and therefore is inaccessible to direct observation. It is about a quarter of the mass-energy of the Universe and manifests itself only in gravitational interaction. Such galaxies, which have recently been discovered through observations, challenge the cosmological model used by astronomers. We are talking about the Lambda-CDM model, ΛCDM is an abbreviation for Lambda-Cold Dark Matter, a modern standard model in which a spatially flat Universe is filled, in addition to ordinary baryonic matter, with dark energy and cold dark matter.

Dark matter-free galaxies are badstudied. One way to study the possible mechanisms of formation of these elusive galaxies - for example, ultradiffuse galaxies DF2 and DF4 - is to find similar objects in numerical simulations. In addition, it is important to study their temporal evolution and the circumstances that lead to the loss of dark matter.

Galaxies NGC 1052-DF2 and NGC 1052-DF4, satellitesthe larger NGC 1052, located about 65 million light-years away from us and belongs to the class of ultradiffuse, since their luminosity is very low. It was assumed that with a small number of stars, the proportion of dark matter in such galaxies is especially high, but observations have shown the opposite.

In the LCDM universe, all galaxies shoulddark matter prevails. To figure out why galaxies exist without it, scientists used a cosmological and hydrodynamic simulation called Illustris. In the end, scientists suggested that these galaxies lost most of their dark matter due to gravitational influence and further stratification.

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With the development of astrophysics and approvalhypothesis about dark matter for a number of specialists, the most natural assumption was that dark matter consists of ordinary, baryonic matter, for some reason weakly interacting in an electromagnetic way and therefore not detectable in the study, for example, of emission and absorption lines. Planets, brown dwarfs, red dwarfs, white dwarfs, neutron stars, and black holes could be candidates for such objects.