Astronomers from Yonsei University in Seoul, South Korea, adn other scientific institutions have discovered a rare group of five star-forming dwarf galaxies in the local universe.
dwarf galaxies are low-mass, low-luminosity star systems typically containing several billion stars. Groupings of such galaxies are extremely rare, according to observational data, and the probability that a dwarf galaxy will be part of a group of four or more such objects is less than 0.004 percent.In a new study, scientists describe the discovery of a group consisting of five dwarf galaxies, making the find unique.
The study was based on data from several astronomical surveys, including the Sloan Digital Sky Survey (SDSS). Astronomers have resolute that a group of galaxies is aligned along a straight line in the celestial plane, with three of them having a common direction of rotation. This indicates potential gravitational interactions between them.
The group is located in a relatively isolated habitat about 117.3 million light-years from Earth. The five galaxies are designated D1, D2, D3, D4 and D5, and they form a thin, flat structure extending over 502 thousand light years. the maximum difference in radial velocities between them is 75 kilometers per second, and all galaxies are actively forming stars.
The mass of the entire group is about 60.2 billion solar masses.Among dwarf galaxies, the moast massive is D2, with a mass of 275 million solar masses, and the least massive is D4, with a mass of 14.7 million solar masses. The median stellar mass of the group’s galaxies is 78.7 million solar masses.some galaxies, such as D3 and D4, show signs of tidal interactions, which also confirms their interaction with each other.
The researchers believe that the discovery of such a unique group of dwarf galaxies could considerably expand knowledge of how groups of similar objects form and evolve. The data obtained can definitely help test theories of the formation of large cosmic structures and improve understanding of the mechanisms of the evolution of dwarf galaxies.