re: What's the separation angle between them, in arc seconds?
The second image in R.L.'s 2Keck link says:
[figure 2:
Ground based near-infrared images of the galaxy above, seen without adaptive optics (left) and with laser-enabled adaptive optics (right). In the right hand image, the two nuclei are separated by roughly 0.3 seconds of arc, which is the angular size of a person seen 1000 miles away.]
Congratulations to the Keck AO team. A great effort and nice shot to have been aquired during a test! Thanks for posting it, RL!