How Do Galaxies Form? Newly Discovered Stars Can Solve The Mystery
The mystery of galaxy formation has long baffled astrophysicists. Understanding how galaxies formed is important because without their presence there would be no stars, and hence no life in the universe. Recently, a team of researchers from Liverpool John Moores University have made a discovery that could throw light on how galaxies were created.
According to the researchers, they have been able to collect a large data for hundreds of thousands to millions of Milky Way stars with the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The observations made on the basis of the data enabled the researching team to detect trace stellar families that would otherwise be unnoticeable among a group of ordinary stars.
According to Oxford Journals, the research team led by Dr. Ricardo Schiavon discovered a family of stars with unusual chemical compositions and high nitrogen content. The newly detected star family has properties different from the typical globular cluster stars located in the Milky Way's 'stellar halo,' which suggests that they are linked with clusters that no longer exist.
Scientists know that some of the stars present in the Milky Way were born in the galaxy itself, while others were created in smaller galaxies that were engulfed by our galaxy in the course of time. However, researchers are not very sure which of these processes is the most common.
The prevalent belief held by astrophysicists is that once, a very large number of globular clusters existed in the Milky Way that got totally destroyed. However, the new detected stars are related with the Milky Way's halo and not its disk. According to a report, the "destroyed globular clusters may be the stuff that at least a quarter of the halo is made of." If this theory is confirmed, the result will challenge models of galaxy formation.
Incidentally, globular clusters include a small fraction of all Milky Way stars, but astrophysicists believe that they are important clues to the early stages of how the galaxy formed. Furthermore, the key to understanding how globular clusters formed lies in the stars themselves because a star's chemical composition contains the signature of its predecessors' evolution.
As quoted by The Conversation, "Globular clusters may have contributed substantially to the stellar budget of all galaxies in the universe-something we didn't know before," Ricardo Schiavon said. "This is a riveting prospect that could even come to change our understanding of how galaxies came about, including our own Milky Way."