From Chile, astronomers discover “ghost galaxies”, a new cosmic mystery that has perplexed science

By combining data from the Gemini South telescope, located in Chile, and the DECam Legacy Survey (DECaLS), which contains a huge catalog of images taken from Cerro Tololo and Pachón, a team of astronomers discovered three ultra dwarf galaxies faint They would only contain very old stars, reinforcing the theory about events in the early Universe that could interrupt star formation in smaller galaxies. The galaxies investigated are located in a region of space isolated from the influence of other larger objects. Ultra-faint dwarf galaxies correspond to the faintest type of galaxies in the Universe. These are small, faint structures that usually contain anywhere from a few hundred to thousands of stars – compared to the hundreds of billions of stars that make up the Milky Way, for example – and that are usually hidden discreetly among the countless bright objects. from the sky For this reason, so far it is easier to find them near us, in the vicinity of the Milky Way. However, this does not allow us to understand them very well, since gravitational forces and the galactic corona of the Milky Way can remove gas from dwarf galaxies and interfere with their natural evolution.