An international team of astronomers has discovered a galaxy that existed in the early universe and, in its evolutionary path, was very similar to our Milky Way even at an early stage of its existence.
The research has been published in Monthly Notices of the Royal Astronomical Society: Letters, and an abstract can be found on Phys.org. The galaxy discovered by the scientists was named “Sparkler”. It is embedded in a system of globular clusters and satellite galaxies and is likely to consume them as it grows.
So far from us in all respects, the galaxy reminded researchers of our own Milky Way. After all, our galaxy has gone through a similar history of its formation. It was possible to detect the Sparkler using data from the James Webb Space Telescope, one of the first transmitted by this device to Earth.
The galaxy got its name in honor of the two dozen globular clusters that revolve around it. The latter are dense clusters of stars, of which there are about a million. By comparison, the Milky Way currently contains around 200 globular clusters.
Scientists have determined the age of a distant galaxy at about nine billion years. This means that it began to form about four billion years after the Big Bang. Scientists have already studied globular clusters, determining not only the age of their stars, but also the metallicity of such objects. It turned out that they are as rich in metals as the globular clusters of the Milky Way. The only exceptions were a few star clusters. They were younger than their neighbors. In addition, they are poor in metals. Scientists believe that these clusters are associated with a satellite galaxy, which Sparkler is gradually absorbing. In the same way that the Milky Way did in the distant past.
Astronomers note that the mass of “Sparkler” is only three percent of the mass of the Milky Way. However, they also remind us that we had the opportunity to see a distant galaxy as it was exactly nine billion years ago. It has probably grown in the past and could well grow to the size of the Milky Way. Unfortunately, researchers do not yet have a chance to see the “Sparkler” in the modern universe.
“It appears that we are seeing firsthand the assembly of this galaxy as it grows in mass, initially in the form of a dwarf galaxy and several globular clusters,” said Professor Duncan Forbes, co-author of the study. unique opportunity to study how globular clusters formed at a time when the universe was only a third of its current age.”
