May 24 (UPI) -- Researchers in Germany have run some of the largest-ever galaxy simulations using models they hope will reveal new details about the Milky Way's formation and evolution.
Scientists used several super-computers to run the high-resolution simulations over the course of a few months. The simulations were powered by the most comprehensive physics models yet coded, and incorporated the full scope of cosmic phenomena, including gravity, star formation, gas hydrodynamics and supernova explosions.
The models also incorporated, for the first time, interstellar magnetic fields, and allowed black holes to grow as they pulled in mass over the course of the simulation.
Astronomers have a solid grasp on the structure of spiral galaxies like the Milky Way. A central bulge of aging stars surround a massive black hole. Arms populated by newer stars spread outward from the center. All told, the Milky Way hosts between 100 and 400 billion stars, not to mention billions of tons of gas and dust.
Researchers are less clear on how spiral galaxies are born and evolve -- how they come to assume their recognizable spiral shape. High-resolution models can help.
"The outcome of the Auriga Project is that astronomers will now be able to use our work to access a wealth of information, such as the properties of the satellite galaxies and the very old stars found in the halo that surrounds the galaxy," Robert Grand, researcher at the Heidelberg Institute for Theoretical Studies, said in a news release.
The new models revealed a regular influx of new material from smaller satellite galaxies.
"For a spiral galaxy to grow in size, it needs a substantial supply of fresh star-forming gas around its edges -- smaller gas-rich galaxies that spiral gently into ours can provide exactly that," Grand said.
When coupled with observations from telescopes and space observatories, the findings -- detailed in the Monthly Notices of the Royal Astronomical Society -- could yield new insights into the nature of galactic collisions and growth.