A “spectacular river” of stars has been observed flowing through space in a cluster of galaxies about 300 million light-years away.
These bridges are known as stellar streams, and the newly named Coma Giant Stellar Stream is the longest we have ever seen.
In such a dynamic and gravitationally complex environment as a galaxy cluster, something as weak as a stellar stream would not be expected to persist for long at all.
However, this discovery could be used to study galaxy clusters in more detail, along with the mysterious dark matter contained within them.
Stellar streams are fairly common in the Milky Way. They are thought to be the fragmented remains of dense globular star clusters, broken up by tidal forces in the Milky Way, but they are difficult to identify.
But in recent years, telescope technology and analytical techniques have revealed much fainter objects than we were able to identify in the past; This is the case with the giant Coma stream.
Observational astrophysicist Javier Roman, from the University of Groningen in the Netherlands, was using the Jeanne Rich telescope and the 4.2-meter William Herschel telescope to search for faint structures within the Coma cluster, which contains thousands of known galaxies.
The research team attempted to study galactic halos – diffuse spherical regions of scattered stars and dark matter that comprise the inhabited planes of galaxies.
However, their data revealed the unexpected: a long, extended ribbon of stars, located not within a galaxy, but between cluster galaxies.
This tape is clearly different from the fragile threads of the cosmic web that connect galaxies to each other within clusters as well.
Galaxy clusters are known as chaotic environments due to gravity, where the massive objects in them push and pull each other in every direction.
The researchers found that the stellar stream is not expected to survive for a long time in such an environment, but this environment gives us some clues about the origins of the stream.
They ran simulations and found that such jets, although rare, can form in a galaxy cluster — from a dwarf galaxy pulled apart by the gravity of larger galaxies.
The giant Coma Current also indicates the possibility of finding similar structures in other groups. Researchers hope to use larger telescopes to look more closely at these huge clusters, to find other secrets that we may have missed.
Publish research in astronomy and astrophysics.
