Supercomputers are used by astronomers to simulate the formation of galaxies from the Big Bang 13.8 billion years ago to the present day. An international research team, led by researchers in Lund, has spent a hundred million computer hours over eight years trying to correct these errors. To minimize the sources of error and produce more accurate simulations, 160 researchers from 60 higher education institutions—led by Santi Roca-Fàbrega at Lund University, Ji-hoon Kim at Seoul National University and Joel R. Primack at the University of California—have collaborated and now present the results of the largest comparison of simulations done ever.
“To make progress towards a theory of galaxy formation, it is crucial to compare results and codes from different simulations. We have now done this by bringing together competing code groups behind the world’s best galaxy simulators in a kind of supercomparison,” says Santi Roca-Fàbrega, a researcher in astrophysics.
Three papers from this collaboration, known as the CosmoRun simulations, have been accepted for publication in The Astrophysical Journal; all are available on the arXiv preprint server. In these, the researchers have analyzed the formation of a galaxy with the same mass as the Milky Way. The simulation is based on the same astrophysical assumptions about the ultraviolet background radiation produced by the first stars in the universe, the gas cooling and heating, and the process of star formation.
The new results allow the researchers to conclude that disk galaxies like the Milky Way formed very early in the history of the universe, in line with observations from the James Webb Telescope. They have also found a way to make the number of satellite galaxies—galaxies orbiting larger galaxies—consistent with observations finally solving a problem well known in the community and known as “the missing satellites problem.”
2024-03-03 10:00:03
Source from phys.org