Detection Stream

Visualization by Arpit Arora and Adrian Price-Whelan. Milky Way image credit: Stefan Payne-Wardenaar. Simulated stellar streams arc around the Milky Way. Ah, that ever-elusive dark matter. Although there has been some tantalizing evidence suggesting the detection of a dark matter particle, the data isn’t strong enough to be conclusive. So astronomers continue to rely upon indirect evidence and computer simulations to help us understand the detailed properties of dark matter. A new study in The Astrophysical Journal adds to the simulation column, but with a bit of a twist.1 Most dark matter simulations look at large-scale cosmic structure. They simulate how dark matter affects the clustering of galaxies over time. This new study looks at streams of stars in our galaxy instead. Stellar streams form when a dwarf galaxy or star cluster collides with a larger galaxy. The gravitational interactions cause stars to spray out in streams that then orbit the large galaxy. Most of these streams…