Colliding Galaxies

In this segment of our “How far away is it” video book, we cover interacting or colliding galaxies.

small D = 00080 NGC 2207 and IC 2163

IDL TIFF fileWe begin with the trajectory of Andromeda with respect to our Milky Way. They are on a collision course. We describe what it means for galaxies to collide given the great distances between stars within each galaxy. We then take a look at some of the interacting galaxies photographed by the Hubble Telescope. These include: NGC 2207 with IC 2163; Apr 256; NGC 6240; the Tadpole Galaxy; UCG 1810 with UCG 1813; The Mice; the spectacular APR 147; NGC 454; and peculiar galaxy NGC 7603 with its multiple red-shift objects;.small D = 00420 Tadpole Galaxy - UGC 10214 copy

Next, we discuss how we go about seeing a process that takes a billion years by observing interactions at various stages along the process as understood by computer simulations. Here are a few that illustrate the phases of an interaction: the initial approach – NGC 6786 with LEDA 62867; first contact – VV 304A with VV 304B; penetration – Mayall’s Object; out the other side – ESO 77-14; wrap around – VV 705; merge – The Owl. We then show the computer simulation of a collision and highlight the above galaxies along the way.

We end with another simulation. This time it’s the collision between Andromeda and the Milky Way.