Astronomers believe they’ve mapped a necessary sequence of events that shaped our galaxy 10 billion years ago. In a paper published in Nature Astronomy today, researchers from the Instituto de Astrofisica de Canarias(IAC) share their findings that a dwarf galaxy, Gaia-Enceladus, as soon as collided and merged with the early Milky Method. Their discovery provides a new understanding of how the Milky Way formed.
Astronomers previously believed that the galaxy was made from two separate units of stars, however exactly how or after they came together was a mystery. Utilizing the Gaia space telescope, these researchers have been able to take more exact measurements of the position, brightness, and distance of roughly a million stars. They also appeared at the density of “metals,” or elements without hydrogen or helium, that the stars contain. The researchers decided that both units of stars are about the same age however that one was set into “chaotic motion,” proof of a galaxy collision.
The researchers believe Gaia-Enceladus collided with the young Milky Way about 10 billion years in the past, and over the course of thousands of years, the Milky Way consumed the dwarf galaxy. The researchers additionally determined that the collision contributed to a four-billion-year stretch of star formation, and gas from that exercise settled to form the “thin disk” that runs by means of the center of the Milky Way. They imagine the remnants of Gaia-Enceladus finally shaped the halo of the present-day Milky Way.