Mysterious 'Wave' of Star-Forming Gas May Be the Largest Structure in the Galaxy

Apparently "the team's paper offers no speculation about the event that could have created the Radcliffe Wave" - so we are free to do it - but the closeup shows a hole in the wave at its center [ https://www.sciencealert.com/a-colo...he-largest-gaseous-structure-in-the-milky-way ]. If a dark matter lump punched a hole in a star structure (here the galactic disk) to leave a sinusoidal perturbation, it would not be the first suspected such, e.g. the GD-1 star stream event [ http://www.astronomy.com/news/2019/06/dark-matter-may-have-punched-a-hole-in-the-milky-way ].

FWIW, the first link has a reference to Gould's Belt [ https://www.cfa.harvard.edu/gouldbelt/gouldsbelt.html ].