AKs, call or raise the flop?

[bozlax]

Should I call this planning to raise the turn improved? Or should I raise to try and thin the field? Or would I be raising for value?

MP3 had insignificant stats (only 27 hands, and I hadn't seen him showdown a single one).

Party Poker 0.5/1 Hold'em (9 handed) converter

Preflop: Hero is CO with K[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/spade.gif[/img].
UTG calls, UTG+1 calls, MP1 calls, <font color="#666666">1 fold</font>, MP3 calls, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, SB calls, BB calls, UTG calls, UTG+1 calls, MP1 calls, MP3 calls.

Flop: (14 SB) T[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(7 players)</font>
SB checks, BB checks, UTG checks, UTG+1 checks, MP1 checks, <font color="#CC3333">MP3 bets</font>, <font color="#CC3333">Hero ?