Close encounter more than 10,000 years ago stirred up spirals in accretion disk

Dr. Lu Xing, an associate researcher from the Shanghai Astronomical Observatory (SHAO) of the Chinese Academy of Sciences, along with collaborators from Yunnan University, the Harvard-Smithsonian Center for Astrophysics, and the Max Planck Institute, have used high-resolution observational data from the Atacama Large Millimeter/submillimeter Array (ALMA) to discover a massive protostellar disk in the Galactic Center and determine how its spiral arms were formed.