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Galactic Winds Push Researchers To Probe Galaxies At Unprecedented Scale

on August 12, 2017 - 6:53am
A density projection of a cool cloud getting destroyed as it is exposed to an outflow’s hot wind. Rather than getting pushed, the simulation shows the cold material instead becomes gradually heated until it is fully incorporated into the hot wind. Courtesy/Evan Schneider, Princeton University
OLCF News:
When astronomers peer into the universe, what they see often exceeds the limits of human understanding. Such is the case with low-mass galaxies—galaxies a fraction of the size of our own Milky Way.
These small, faint systems made up of millions or billions of stars, dust, and gas constitute the most common type of galaxy observed in the universe. But according to astrophysicists’ most advanced models, low-mass galaxies should contain many more stars than they appear to contain.
A leading theory for this discrepancy hinges on the fountain-like outflows of gas observed exiting some galaxies. These outflows are driven by the life and death of stars, specifically stellar winds and supernova explosions, which collectively give rise to a phenomenon known as “galactic wind.” As star activity expels gas into intergalactic space, galaxies lose precious raw material to make new stars. The physics and forces at play during this process, however, remain something of a mystery.
To better understand how galactic wind affects star formation in galaxies, a team turned to high-performance computing at the Oak Ridge Leadership Computing Facility (OLCF), a US Department of Energy (DOE) Office of Science User Facility located at DOE’s Oak Ridge National Laboratory (ORNL). They scaled up their Cholla hydrodynamics code on the OLCF’s Cray XK7 Titan supercomputer to create highly detailed simulations of galactic wind.