Powerful supercomputers allow first simulation of Milky Way-like galaxy
The new simulation, called "Eris" by researchers at the University of California, Santa Cruz, and the Institute for Theoretical Physics in Zurich solves a long-standing problem that had led some to question the prevailing cosmological model of the universe.
"Previous efforts to form a massive disk galaxy like the Milky Way had failed, because the simulated galaxies ended up with huge central bulges compared to the size of the disk," said Javiera Guedes, who recently earned her Ph.D. in astronomy and astrophysics at UC Santa Cruz and first author of the study
The Eris galaxy is a massive spiral galaxy with a central "bar" of bright stars and other structural properties consistent with galaxies like the Milky Way.
Its brightness profile, bulge-to-disk ratio, stellar content, and other key features are all within the range of observations of the Milky Way and other galaxies of the same type.
According to coauthor Piero Madau, professor of astronomy and astrophysics at UC Santa Cruz, the project required a large investment of supercomputer time, including 1.4 million processor-hours on NASA's state-of-the-art Pleiades supercomputer, plus additional supporting simulations on supercomputers at UCSC and the Swiss National Supercomputing Center.
"We took some risk spending a huge amount of supercomputer time to simulate a single galaxy with extra-high resolution," Madau said.
"This is the first simulation that is able to resolve the high-density clouds of gas where star formation occurs, and the result is a Milky Way type of galaxy with a small bulge and a big disk.
"It shows that the cold dark matter scenario, where dark matter provides the scaffolding for galaxy formation, is able to generate realistic disk-dominated galaxies," he added.
The paper will be published in the Astrophysical Journal.