This new image from Hubble shows what happens when a spiral galaxy (like the Milky Way) collides into a lenticular galaxy (an intermediate between an elliptical and a spiral galaxy).
The Hubble website explains more:
The image also reveals further evidence of the collision. There is a bright stream of stars coming out from the merging galaxies, extending out towards the right of the image. The bright spot in the middle of the plume, known as ESO 576-69, is what makes this image unique. This spot is believed to be the nucleus of the former spiral galaxy, which was ejected from the system during the collision and is now being shredded by tidal forces to produce the visible stellar stream.
It's worth noting that the Milky Way Galaxy is scheduled to collide with the Andromeda Galaxy in about 4 billion years (both are spirals). The whole thing will go down like this:
Image: ESA/Hubble & NASA; Acknowledgement: Luca Limatola.