This simulation flies into a tangle of merging galaxies, ultimately zooming into an active supermassive black hole, or quasar, surrounded by a swirling disk of material called an accretion disk. A filamentary stream of gas has been wound up into the disk, funneling gas in at a rate sufficient to fuel the brightest known quasars in the universe. Near the end of the simulation, magnetic fields rip away the angular momentum from the rotating disk, which allows material to spiral in further and further until it reaches the event horizon of the black hole, where it can't escape.

In this simulation, which represents one moment in time, the scale zooms in by a factor of a billion. The colors show the density of the gas, with brighter colors representing higher densities.

credit: Caltech / Phil Hopkins Group