This would have to be a Black Hole, but we can't really detect and name them at the distance of several million light years. This galaxy also has not one, but two massive black holes at its center. There is a little confusion here. The great mass of a galaxy and its central black hole distorts the geometry of space around it, acting as a sort of lens for light. If it lies between us and a more distant galaxy, it can distort the image of that distant galaxy, producing two, three or more distorted images of the other galaxy.
Dwarf galaxies exist in all sizes and shapes, except spiral.
They contain only a few million stars and are hard to see behind the foreground stars of our galaxies. It's kind of arbitrary where you draw the line. I was always interested in the natural world, and went through nuclear physics to gamma ray physics to x-ray astronomy to the study of galaxies. I, and some of my colleagues, also found inspiration in science fiction. Well, as usual, there are lots of theories.