The Milky Way was formed from the merger of thousands of smaller galaxies

Three-year simulation findings show that the building blocks of life, such as carbon and iron, are the result of the destruction of the first stars at the dawn of the cosmos.

New findings show that long before it became the bright spiral galaxy it is today, the Milky Way was a massive, turbulent mass of thousands of small galaxies. The results of this research claim that during the first 2 billion years after the Big Bang, the region of the universe that later formed our present home was filled with thousands of smaller galaxies of various sizes and shapes. Over time, these systems collided and merged to eventually form the current single galaxy.

Harley Katz, assistant professor of astronomy and astrophysics at the University of Chicago and one of the co-authors of this study, pointed out in a statement that the physics governing the moments after the Big Bang has a direct effect on the structure and characteristics of our local universe today. To better understand the mechanisms of the early universe, astronomers are developing advanced computer models that reconstruct how the universe evolved by encoding natural laws. This study, which is the result of 3 years of supercomputer simulations, is considered to be the most accurate trace presented of how a galaxy like the Milky Way was formed and provides a solid benchmark against observational data.

Megatron; A tool for simulating the structure of the Milky Way galaxy

Thanks to its ability to penetrate the most distant parts of the early universe, the James Webb Space Telescope has repeatedly challenged previous models with its discoveries. The discovery of very bright primordial galaxies and a group of compact galaxies known as the "Little Red Dots" are among those that have shown that old computer models need to be updated to match the complex physics of the early universe.

To fill this void, researchers have created a new simulation set called "Megatron". By tracking ancient gases, starlight, and chemical reactions in the time frame of 180 million to 2 billion years after the Big Bang, this system predicts special optical signatures of virtual galaxies. Since the James Webb telescope collects similar spectral data over the same time period, it is possible to directly match the simulations to real observations to correct for earlier errors.

The simulation also tracks the birth, evolution and death of the first stars; An event that has led to the production of the basic elements that make up life. "Martin Ray", a theoretical astrophysicist at the University of Beth, UK, emphasized that the simultaneous examination of these simulations and James Webb's observations has made it possible to accurately test the models of the first generation stars in an unprecedented way.

The details of this scientific achievement have been published in The Open Journal of Astrophysics.

Scientists' simulations begin 180 million years after the Big Bang, a period when space was empty of stars and galaxies and only pure gases existed. With the passage of time, the first stars appear and mark the "Cosmic Dawn". Then the death of these stars disperses heavy elements such as carbon, oxygen and iron in the surrounding gases, which are the cornerstones of the formation of stars and planets. The process of merging the Milky Way continued even after the end of this simulation in the 2 billion years of the universe; So that the merger with the Sagittarius Dwarf Galaxy started 6 billion years ago and is still going on. British researchers are now working on the next generation of these simulations to include more complex phenomena such as active black holes.