Astrophysicists Produce First Realistic Simulation of Milky Way's Formation

Astrophysicists have been trying for nearly two decades to produce a model capable of simulating the genesis of a spiral galaxy — the class of flat, rotating disk galaxies to which our own Milky Way belongs. And now, they've finally done it.


Featured here is a time-lapse video of the world's very first simulated formation of a spiral galaxy, the final product of an international collaboration between astrophysicists, astronomers, and a couple of very, very powerful computers.

How exactly does one go about modeling an entire galaxy? How else: mathematics. The simulation used to model the genesis of the galaxy featured up top is based on calculations first published in a 2010 issue of the journal Nature by Lucio Mayer — an astrophysicist at the University of Zurich — and UC Santa Cruz astronomer Peiro Madau.

Mayer and Madau collaborated with Ph.D. students Javiera Guedes and Simone Callegari to refine the original calculations and generate the simulation you see today, but not without a bit of technical assistance.

Illustration for article titled Astrophysicists Produce First Realistic Simulation of Milky Way's Formation

To run the numbers necessary to generate the simulation, the researchers needed the help of two high-performance supercomputers: the Cray XT5 "Monte Rosa" at Zurich's Swiss National Supercomputing Center, and the NASA Advanced Supercomputer Division's "Pleiades." The model comprises 790 billion solar masses and over 18 million particles to give rise to spiral formations like the one pictured here. The left half of the image is a still taken from the galaxy-formation simulation, with gas labeled in red and stars in blue; the right half is a false-color picture of the spiral galaxy M74, with the same gas and star labeling. The researchers estimate that a regular computer would have needed upwards of 550 years to churn through the simulation's calculations.

Illustration for article titled Astrophysicists Produce First Realistic Simulation of Milky Way's Formation

The researchers' ability to model galaxies has enormous implications for the fields of astronomy and astrophysics. For one thing, it serves to demonstrate that many of science's unifying theories of astrophysical behavior are correct; while previous attempts to model spiral galaxies have failed to account for the formation of galaxies of various sizes, the simulation generated by Mayer and his colleagues can realistically model the genesis of large and small spiral galaxies alike. (Pictured here is an edge-on view of the simulated galaxy, positioned above a real image of our Milky Way galaxy as you would see it in infrared.)

Equally impressive is that, while the simulation doesn't model exactly the formation of any spiral galaxy in particular, it's already dishing out spoilers about discoveries yet to be made in our very own Milky Way — predicting, for example, the existence of stars and gasses along the outer reaches of the galaxy that our modern probes and telescopes have yet to discover.


The researchers' latest calculations and details on the simulation are to be published in The Astrophysical Journal
(A direct link to the article will be provided when the e-copy of the publication goes live.)

All images via Lucio Mayer




That formation looks less tasty than I imagined it....