A Smithsonian-led team has published Lumina, a large simulation of the universe’s first two billion years that models ordinary matter, dark matter and radiation to help astronomers test explanations for how the universe changed against telescope observations.
The research was led by scientists at the Center for Astrophysics | Harvard & Smithsonian. It appears in Monthly Notices of the Royal Astronomical Society. The simulation covers a region 500 megaparsecs, or about 1.6 billion light-years, across.
It tracks gas, dark matter, stars and radiation across large distances in the universe. It follows how early galaxies formed. It also follows two major changes called hydrogen and helium reionization.
During these changes, radiation from early stars and active galactic nuclei changed the state of gas between galaxies. Researchers can compare Lumina’s predictions with observations from the James Webb Space Telescope and other observatories to assess whether current models explain what telescopes detect. The team says the simulation’s large volume can help capture rare objects that smaller models may miss.
The team also says it can capture broad cosmic environments that smaller models may miss. Lumina is a theory-based model, not a direct reconstruction from telescope images. Its value lies in producing predictions that observations can test.