[Lmn55d]

that's not a bad spot to check behind on the turn. AJ has 3 outs and there are only 3 combos of AT. If checkraised you could have up to 5 outs. If it's a guy who will call you down with lower pocket pairs I like the bet.

As for the river, I don't like a bet. I think his most likely hands are a low pocket pair which you beat, a hand like AJ/AT that might even call, or a queen that is afraid of the king.

EDIT: Actually there are 8 combos of AT that have 7 outs so I wouldn't consider a turn check. I'm dumb.