Astronomers have solved a centuries-old puzzle surrounding one of the Universe's oldest and densest star systems.
Globular clusters of stars were first discovered in the 17th century and scientists have long-debated how they formed.
Many stars in our own Milky Way and other galaxies are found in these tight clusters of several million stars.
Ultra-high resolution computer simulations
Now a team of researchers, including astronomers from our Department of Physics, has used ultra-high resolution computer simulations to show how such clusters likely formed in the early Universe.
Their simulations traced the Universe's 13.8-billion-year history in unprecedented detail.
They show that a fraction of stars in galaxies are born naturally in this tightly clustered way, leading to results like those seen through telescopes.
New class of ancient star systems
The research also unexpectedly revealed a new class of ancient star systems called globular-cluster-like dwarfs.
The simulated star clusters were seen to have a sizeable amount of dark matter – the mysterious substance that binds galaxies together – within them.
This new class resemble globular clusters, but due to the dark matter they are classified instead as small, or "dwarf", galaxies.
We never expected these star clusters to emerge when we designed the simulations. Seeing them was a genuine surprise, and we're now delving into their properties to see how they match up to the real deal seen through telescopes.
If found in the real Universe, such objects could become prime sites for the search for pristine, metal-free stars born in the early Universe.
They would also provide new locations to explore the nature of dark matter.
