My thoughts:

I think a fold is in order. Best case scenario is raising with a hand range (A9-109 and A10-A3) wich would mean you have a little more than 6 outs giving you approx. 8.3:1 to call when its 8.5:1 to you. If you start discarding hands like A3, A4 or A5 he'd raise you with on the turn, your odds cut down pretty much to a size where it would be unprofitable to call. Pretty read-dependent decision as it seems where you have to decide how likely this opponent is raising you with a weak ace (more or less covered by a nine), to go for a check-check on showdown but tries to increase his chance of making you fold a better ace.