I want to explain the explosion that sent the enormous mass from the black hole; The Blackhole has a center of gravity because space is in a vacuum. The stars, planets, anything else that gets trapped within the gravitational pull. Eventually, what goes in must come out. The center of the black hole could not support the enormous mass it had pulled in. hence the explosion. The mass farther away from the black hole is brighter because it is the center of the mass ejected first. The tail end is just that the tail of the explosion. There is also a tail in the front of the mass because when the mass slowed down, the lighter material extended to form front tails. You have just witnessed the birth of a new Galaxy. All the mass ejected from the black hole went beyond the boundaries of the galaxy. And will form a new Galaxy.