Where is the gallery template "single.php" file?

I’m having trouble identifying which Twenty Eleven template file controls the display of the default WordPress gallery. This is the gallery that displays when in your post you use a command like this:

[gallery link="post" ids="2518,2519,2520,2521,2522,2523,2524,2525,2526"]

Specifically I’m looking for the file or function that controls the “single.php”-ish individual display of an image once its thumbnail has been selected from the main gallery.

Thanks!