Researchers have identified a distant galaxy named REBELS-25, which exhibits surprising similarities to the Milky Way, potentially altering our understanding of galaxy formation.
Led by astronomers from Leiden University in the Netherlands, the study indicates that REBELS-25 is more structured than expected for its age. Despite being much younger than the Milky Way, it demonstrates a well-defined rotation and organization, contrasting with the chaotic nature typically associated with early galaxies.
The light from REBELS-25 reached Earth only 700 million years after the Big Bang, a remarkably short time for a galaxy to achieve such order. Lucie Rowland, a doctoral student at Leiden and the study's lead author, stated, "Seeing a galaxy with such similarities to our own challenges our understanding of how quickly galaxies evolve in the early universe."
The observations were made using the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile. The research team also found indications of potentially more developed features, such as spiral arms, and plans to conduct further observations to confirm these structures.
Andrew Blain, an astrophysics professor at the University of Leicester, noted that while REBELS-25 is unusual, it does not revolutionize current theories. He emphasized the importance of ALMA in detecting galaxies that were previously only simulated, stating, "Without ALMA, it would have been impossible to identify such an example due to the faintness of individual cases."
Dave Clements, an astrophysicist at Imperial College London, remarked on the unexpected discovery of REBELS-25, suggesting it raises questions about the chaotic conditions of the early universe and whether galaxies typically undergo a similar peaceful phase.
The study, currently available as a preprint, has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.