Interacting galaxies make for a very nice photo subject, although often they are quite small and you’ll need a long focal length to capture them properly. Last year on La Palma I captured the Hickson 44 group of interacting galaxies, which is still one of my favourite pictures.
When Galaxies Collide – Youtube lecture
I stumbled onto this great lecture by GreshamCollege on Youtube; When Galaxies Collide by Professor Carolin Crawford. While showing some great Hubble photo’s of interacting galaxies, she explains the interaction that took place and what stage of this interacting the current captured moment by Hubble is showing. She shows animations of simulations of these interactions and then freezes frame to show the comparison with the ‘real world’.
Just an amazingly interesting talk with great photo’s. Go watch it!