Researchers have released a set of cosmological simulations named MEGATRON, connecting James Webb Space Telescope observations of infant galaxies with chemical fossils in the Milky Way. Published across four studies in the Open Journal of Astrophysics, the project runs from 2023 to 2030 to model early stellar evolution.
Supercomputers Model The Cosmic Dawn
A collaboration led by researchers at the University of Bath, alongside the University of Chicago in the United States and the Institut d’Astrophysique de Paris in France, completed three years of intensive computation on high-powered supercomputers. The project, named MEGATRON, traces how the region that eventually became the Milky Way evolved from thousands of smaller galaxies during the early days of the universe. According to the collaboration, the computational models explore how the first stars and galaxies lit up a dark cosmos and enriched it with chemical elements.
The initial findings span four papers published in the Open Journal of Astrophysics, with further papers expected before the project concludes in 2030.
MEGATRON Project Bridges Telescope Data with Stellar Archaeology
Astronomers have historically relied on two distinct datasets to study cosmic history: direct observations of distant infant galaxies and the chemical composition of ancient stars closer to home. The MEGATRON project provides a physical bridge between these two perspectives. As Dr. Martin Rey of the University of Bath explained in a statement reported by Space, The JWST gives us a direct glimpse of the infant cosmos, while stellar archaeology allows us to study the relics of those earliest times in our own galactic neighborhood
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“Together, these complementary observations allow us to test competing models of the first stars in ways that weren’t previously possible.”
Dr Martin Rey, Department of Physics at the University of Bath
The simulations show that capturing the complex interplay between starlight, gas, and newly forged elements is essential for interpreting both young galaxies seen by JWST and the chemical clues preserved in ancient local stars. Harley Katz noted that the model directly predicts what the early Milky Way would have looked like to space observatories like the James Webb Space Telescope.
Simulations Solve Dwarf Galaxy Iron Mystery
Typically, less massive galaxies contain less iron. One of the specific mysteries addressed by the simulations involves the iron content of the faintest dwarf systems orbiting the Milky Way.
The MEGATRON simulations suggest that the culprit behind this anomaly is explosions from an exotic type of star left over from right after the Big Bang. These Population III stars consisted exclusively of hydrogen and helium. When they died in supernova explosions, they produced more iron than other supernovae do.
Researchers Track Non-Equilibrium Physics In Early Stars
Simulating the transition from pristine primordial gas to metal-enriched star-forming regions required tracking physical processes that standard models often simplify. The MEGATRON models incorporated non-equilibrium physics, recognizing that real galaxies evolve constantly rather than maintaining chemical equilibrium.
The elements that make our world and life possible – carbon, oxygen, iron and many others – were forged by stars.
Dr Martin Rey, University of Bath
The collaboration plans to utilize its awarded supercomputing hours to run higher-resolution models with more complete physical frameworks. Published across four studies in the Open Journal of Astrophysics, the project runs from 2023 to 2030 to model early stellar evolution.