July 4, 2022
Scientists have revealed how "dark galaxies" appeared in the universe

Scientists have revealed how “dark galaxies” appeared in the universe

Russian scientists at Moscow State University, along with colleagues from the United States, France, the United Arab Emirates and Japan, have identified the mechanism by which ultra-diffuse dark galaxies (UDG), that is, those with few visible stars, are propagated.

Previously, it was believed that extremely low-light galaxies formed when the intergalactic medium released interstellar gas outside the galaxy, stopping the star-forming processes.

The intergalactic medium consists of hot plasma, which reaches temperatures of tens of millions of degrees. Although this plasma is very rare, it is galactic-wide dense enough to interact with matter.

In the study published In the journal Nature Astronomy, astronomers analyzed 11 small-mass galaxies in the Cabeleira de Berenice group, located 323 million light-years from Earth, and in the Abell group, located 486 million light-years from our planet.

These galaxies are similar to super-diffuse galaxies, but they are still very bright for being small.

Galactic Abell cluster 3827

Scientists established The aforementioned galaxies have tails of exogenous gas and newly formed stars. These tails have evolved due to interaction with the intergalactic medium, which removes matter from galaxies.

According to researchers’ estimates, all these galaxies will become very scattered in the next 10 billion years.

When galaxies lose their mass, the average distance between the center and the stars increases, and it is this expansion that makes them so spread out. For many galaxies, this process ended 180-970 million years ago, and at least 44% of ultra-diffuse galaxies arose in this way.