File:ToomreandToomreF23.png

Fair Use Rationale
The image is cut from Toomre and Toomre's 1972 paper found here. I believe it qualifies as fair use in the article Alar Toomre where it's used for critical commentary on his seminal 1972 paper from which the figure is culled - the commentary is specifically about the figure and how well it matches observations.

Specifically:
 * 1) No free equivalent exists or can be created - the image itself, and how well it matches the observed Antennae galaxies is the heart of the issue.
 * 2) The image creates no problems for commercial opportunities - the image is already distributed freely.
 * 3) The image represents a minimal use - a single graph from a 40-some-odd page paper. One graph is the minimum that can be used to explain the graphs
 * 4) The graph was published in 1972 by the Astrophysical Journal
 * 5) An encyclopedic image relevant to seminal-type work on N-body simulations
 * 6) It meets the image use policy.
 * 7) The article is used in at least one article, Alar Toomre
 * 8) The image contributes significantly to the article. Merely saying that the images were a pretty good match does not adequately capture the circumstances.  Readers really need to be able to see how the image looks compared against images of the Antennae galaxies to understand the nature of the work.
 * 9) The image is used only in the article namespace
 * 10) The copyright holder is probably the Astrophysical Journal - their stated copyright policy is that they retain the rights to all copyrightable material they publish.  Unless this is a change of policy since 1972, the Astrophysical Journal is the copyright holder.  Alar Toomre and Juri Toomre retain some rights, such as the right to reproduce the material as long as they're alive.  In some jurisdictions their transfer of copyright might not be applicable, and they may continue to hold the copyright on the images.