Supercomputer Simulation Shows for the First Time How a Milky Way-Like Galaxy Forms
Eris
IMAGE BY J. Guedes and P. Madau via UCSB
It took nearly a year of high-powered number crunching on various supercomputers, but researchers from the University of California Santa Cruz campus and the Institute for Theoretical Physics in Zurich, Switzerland have finally produced a computer simulation of a galaxy that looks much like our own. That may not sound so huge at face value, but it actually is the first high-resolution simulation of its kind that has turned out a galaxy similar to the Milky Way, and it has rescued the prevailing "cold dark matter" cosmological model of how our disc galaxy formed from a good deal of doubt.
That doubt arose from the fact that when previous, lower-resolution models were run based on that cosmological model, a huge central bulge emerged in the galaxy--a bulge that is absent from all but the center of the Milky Way (another way of saying that: there was more bulge and less disc, whereas the Milky way is more disc, less bulge). This had some physicists thinking that perhaps there was a flaw in the cosmological model itself, which seemed incapable of producing via simulation the flat, spiral-armed qualities consistent with observations of our galaxy.