Astronomers Discover Solution to 400-Year-Old Mystery and Identify a Novel Type of Star System
In 1665, astronomer Abraham Ihle first observed a cosmic object known today as M22, which belongs to a class of objects called globular clusters. These clusters have long been a source of mystery for scientists due to their unique characteristics. Unlike dwarf galaxies, globular clusters are made up of millions of very old stars but show no traces of dark matter, a fact that has puzzled researchers for centuries.
Simulation Reveals New Insights
A team from the University of Surrey conducted high-resolution cosmological simulations known as EDGE, using the UK supercomputer DiRAC. These simulations successfully reproduced the natural formation of both globular clusters and a new type of system called Globular Cluster-like Dwarfs (GCDs) for the first time. These GCDs are similar to globular clusters but contain dark matter, presenting an intermediate system between globular clusters and dwarf galaxies.
Discovering New Cosmic Candidates
GCDs have properties that combine aspects of both globular clusters and dwarf galaxies, with an intermediate size, low metallicity, and the presence of dark matter. Some known satellites of the Milky Way, such as Reticulum II or Boötes V, may belong to this newly identified category of cosmic objects. This discovery suggests that these objects have been overlooked in our cosmic neighborhood.
Implications for Dark Matter Research
The existence of GCDs not only helps to unravel the mystery of globular clusters but also offers a new opportunity to test dark matter models. If GCDs are found in the expected quantities, they could serve as a natural laboratory for differentiating between cold, warm, or hot dark matter hypotheses. Additionally, the metal-free stars within GCDs make them ideal places to search for remnants of the first stellar generations, known as population III stars, which have eluded detection thus far.
