Hubble has detected strange blue ‘dots’ of young stars

The astrophysicists work on a puzzle black matter they are looking for dwarf galaxies It contains dark matter but may be too faint to be detected earlier. The Standard Cosmic Model It is expected that there will be a large number of these galaxies Dwarves around large galaxies like Milky Way.

It is generally possible to hunt these dwarf galaxies faint galaxies near galaxy use radio telescopes Like the ones in the network very large array in New Mexico (USA). Technically, it is about the study of radiation radio From Clouds From Gasfor example Across famous 21 cm line of hydrogen. Several promising gas clouds that could be associated with faint dwarf galaxies have been discovered by a groupAstronomy scientists Led by Elizabeth Adams of the Netherlands Institute for Radio Astronomy.

These gas clouds were thought to be associated with the Milky Way, and most may be. But when the difference is — with researchers like David Sand, associate professor of astronomy at the University of Arizona, or Michael Jones, a postdoctoral researcher at the University of Arizona.UArizona Steward . Observatory and lead author of an article about these withdrawals and deposited in free access on arXiv He wanted to find him stars Associated with them and dwarf galaxies, they had surprises.

Thus, an unprecedented association of young blue stars forms a group called SECCO1 and note with telescope Hubble actually happened to be ingalaxy cluster Virgin. It is located at an estimated distance of 48 to 72 millionlight yearsIt was discovered by a famous French astronomer Charles Messier (1730-1817) is best known for creating the famous catalog of deep-sky objects that bear his name.

Two hypotheses for the origin of the mysterious “blue dots”

Other Notes with Hubble and Tools VLT Eso in Chile for the presence of ” dots Similar schemes with never before seen features. Thus, most stars in each system are very blue and very young, rich in heavy elements that astrophysicists call metal which are, in fact, just cores other than those inhydrogenI’helium and theirs isotopesall immersed in clouds containing very little atomic hydrogen that forms well at the end of structures the size of a dwarf galaxy.

Article on arXiv It reports five blue “spots” far from the Milky Way and the distant galaxies in a group Virgowith which it is likely related, from a distance of up to 300,000 light-years.

The presence of blue stars is almost exclusively, and therefore young people, with no yellow elf where red dwarf It is really detectable, and indicates that star formation is recent. However, the presence of many minerals suggests that the gas from which these stars formed must have been in a large and ancient galaxy that had time to chemically evolve with several generations of stars. nuclear synthesis The stars end their lives in them supernovae, thus ejecting the products of this nuclear structure into the galaxies. So we must see, as in the Milky Way, red dwarfs And yellow in abundance.

To solve this contradiction, two theories can be called, all of which involve masses Gas emitted from a large galaxy. The first assumes the effect of tidal forces It is exerted by one large galaxy on another, forces that would therefore rupture the gas. Another theory involves a galaxy rapidly colliding with a mass of hot plasma in a galaxy cluster. It can be shown that the shock produces a the pressure Capable of rapidly ripping a mass of gas out of the galaxy. Then we talk about an effect called dynamic pressure abstraction (ram pressure stripping in English).

The researchers are leaning more towards the second hypothesis because in order to get the blobs despite everything very isolated from the surrounding galaxies, they must move quickly, which is inconsistent with the hypothesis of the mechanism with tidal forces.