Introduce the wheel galaxy
In the universe, the galaxy galaxies run galaxies with galaxies at high speed in the universe. When they catch up to another galaxy with galaxy nuclei, if they run at similar speeds, they will swallow each other and form a larger galaxy.
The galaxy looks like a wheel-like ring, the external halo is a lot of newly formed stars. Astronomers believe that the galaxy was originally a galaxy-like spiral galaxy, because with another galaxy collided, it becomes today's wheel-like. They estimated that about two hundred million years ago, a smaller galaxy crashed into the center of a larger galaxy. As the gravity of the larger galaxy center is twisted by the small galaxies, resulting in shock waves, from the central rushed to the outside, so that the outer nebula pressure, the formation of new stars. Although people find two small galaxies next to the wheel galaxy, but more that they have nothing to do with the collision, the original collision of the galaxy has long been left, is estimated to be located in the distance of 250,000 light years.
The Cartwheel Galaxy (ESO 350-40) is a lenticular galaxy located in the feathered seat, 500 million light years away from the Earth, and its diameter is about 150,000 light years.
