The field of quantum mechanics all fundamental forces are carried by particles. For instance, light is made up of massless particles called photons that carry the electromagnetic force. Likewise, the graviton is the theoretical particle that would carry the force of gravity. Scientists have yet to detect gravitons, which are tricky to find because they interact so weakly with matter.
The accretion disk(circular rotating matter) solar system matter & nova remains/ binary star sucked into the hole.and jet (yet visible matter,subatomic breakdown, radiation) of a supermassive black hole. All spiral galaxies seem to have supermassive black holes at their center. That and dark matter (invisible) produce the galaxy the high speed of rotation. Jet is the still visible radiation from its breakdown of matter under it's gravity.