Massive Black Holes, millions to billions of times more massive than our sun, exist in the centers of most galaxies. However, the formation and evolution of these objects through accretion of gas and mergers with other black holes is still a great mystery. LISA, a future space-based gravitational wave detector, will illuminate this process dating back to early times in the universe by measuring gravitational waves (GW) from mergers of these black holes. This visualization captures these processes over time by showing bursts of GWs from the merger events in the Illustris1 large-scale cosmological simulation (Sijacki et al 2015). The animation illuminates the spatial, temporal, and amplitude distributions of the mergers in the simulation.
Mergers of massive black holes from the centers of galaxies are shown from the Illustris1 simulation. You are seeing bursts of gravitational waves which will be measured by LISA, a future space-based gravitational wave observatory.