What is at the center of the galaxy?

The center of the (Milky Way) galaxy is a black hole. Think about a heterogeneous mixture of materials of different densities placed under the influence of gravity. Heavier materials tends to stay inner. Expect the same here. The heavier black hole is ought to stay at the center of the galaxy. Answer Scientist think that its a super black hole (I forgot what its really called), think of it as a egg, the yolk is the center and the white is the actual galaxy part. If you didn't know, the Andromeda galaxy has two 'yolks': there appear to be two main concentrations of mass near the center; some astronomers think this may be a sign that the Andromeda galaxy is the result of the collision of two smaller galaxies. A massive black hole is believed to be in the center of the Milky Way, and is now believed to be at the center of most, if not all, galaxies.
Current cosmology holds that a supermassive black hole
typically resides at the center of a galaxy.