New Delhi: Globular clusters are roughly spherical associations of up to millions of stars, that are stable for incredibly long durations of time. These globular clusters were first discovered in the 17th century and have puzzled astronomers since. All the stars within a globular cluster typically form around the same time, from the same molecular cloud or stellar nursery. They are considered building blocks of galaxies. Unlike galaxies though, globular clusters do not contain dark matter, the mysterious substance that interacts gravitationally with regular baryonic matter, but does not interact with the electromagnetic spectrum at all.
The simulations, that trace back the evolution of the objects in the Universe in a simulated environment called EDGE, revealed multiple pathways for the formation of globular clusters. The simulations also indicated the formation of a new class of object known as globular cluster-like dwarfs. These are dwarf galaxies that resemble globular clusters, and can contain dark matter as well. Visually, globular clusters may resemble these globular cluster-like dwarfs to a great degree. Astronomers may have already spotted objects that are identified as globular clusters or dwarf galaxies, that are actually globular cluster-like dwarfs, including the ultra-faint dwarf galaxy Reticulum II, one of the many satellite galaxies of the Milky Way.
Hunting down globular cluster-like dwarfs
Globular Clusters can be embedded within the disk of the galaxy, but can also orbit the supermassive black hole at the core of a large, evolved galaxy in a wide orbit that is not aligned to the plane of the galaxy. The astronomers intend to look for the new type of objects indicated by the supercomputer simulations, using targeted observations by astronomical instruments, including the James Webb Space Telescope. Globular clusters contain metal-poor stars, similar to the first generation of stars born in the universe. Studying these globular clusters as well as globular cluster-like dwarf galaxies can potentially allow scientists to test theories of dark matter.