Berlin, Germany – Astronomers in a groundbreaking endeavor are unraveling the mysteries of our galaxy, using advanced telescopes to trace the origin of the Milky Way and gain insights into the formation of other galaxies in the early Universe. By harnessing the power of space telescopes like Gaia and James Webb, they can peer back in time and study some of the oldest stars and galaxies, shedding light on the intricate process of galactic evolution.
A recent study revealed two streams of stars, named Shakti and Shiva, with a total mass equivalent to ten million Suns, believed to have merged into the Milky Way approximately 12 billion years ago. These streams existed even before the Milky Way possessed characteristics like a disk or spiral arms, representing some of the earliest building blocks of the galaxy during its formative stages.
Lead researcher Khyati Malhan of the Max Planck Institute for Astronomy highlighted the significance of detecting these ancient structures, emphasizing how these massive fragments collapsed under their own gravitational force to shape the proto Milky Way galaxy. This event occurred when the Universe was still in its infancy, with the earliest galaxies forming around 13 billion years ago.
As the researchers delve deeper into understanding galaxy formation, they use the Milky Way as a crucial test case due to its accessible nature. Coauthor Hans-Walter Rix described the Milky Way as an average galaxy, providing valuable insights into the formation process by analyzing groups of stars with similar ages and levels of heavier elements.
The study also explores the two primary ways stars enter galaxies: through the condensation of gas clouds within an existing galaxy or by capturing stars from a satellite galaxy. While current star formations predominantly occur within gas clouds, the researchers believe that most stars from earlier stages were formed in clumps and then brought into the Milky Way.
With the help of Gaia data, astronomers have identified groups of stars with similar orbits located toward the center of the galaxy, shedding light on the galaxy’s history and the mechanisms that drew stars into its fold. The discovery of streams like Shakti and Shiva suggests a transition from satellite accretion to internal star formation as the primary driver of star additions to the galaxy.
Through meticulous analysis and innovative technology, astronomers are piecing together the intricate puzzle of galaxy formation, unveiling hidden truths about the Milky Way’s origins and evolution. As the universe continues to reveal its secrets, these findings pave the way for a deeper understanding of the cosmos and our place within it.