Seems like he's bluffing with AK or AQ - maybe something like 99. I like the call in position, it makes it seem like you're on a draw. I'd probably have smooth called the turn, but I also like the raise as the board is becoming somewhat scary. I'd let him try to bluff me out one more time on the river (or hope he pairs an A K or Q on the river), then I'd min raise.

In the long run, this is why you make so much more on these hands in position than OOP.