ps 4/180: rivered small flush, what now?

[jus_nutz]

19 remaining in a good old 180 - is it a call? guy is 16.7/7.7 over 80 hands - i put him either on ace rag or a small pp ... i do only beat k high or connectors ... what u think?

PokerStars Tournament, Big Blind is t600 with t50 antes (6 handed) Converter on pregopoker.com

UTG (t24667)
UTG+1 (t10445)
CO (t9030)
Button (t18934)
SB (t4546)
Hero (t9538)

Preflop: Hero is in BB with 4[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/heart.gif[/img]
UTG calls t600, UTG+1 calls t600, <font color="gray">CO folds</font>, <font color="gray">Button folds</font>, <font color="gray">SB folds</font>, Hero checks

Flop: (t2400) Q[img]/images/graemlins/spade.gif[/img] Q[img]/images/graemlins/diamond.gif[/img] A[img]/images/graemlins/heart.gif[/img] (3 players)
Hero checks, UTG checks, UTG+1 checks

Turn: (t2400) 8[img]/images/graemlins/heart.gif[/img] (3 players)
Hero checks, UTG checks, UTG+1 checks

River: (t2400) Q[img]/images/graemlins/heart.gif[/img] (3 players)
Hero checks, UTG checks, <font color="red">UTG+1 bets t1200</font>, <font color="gray">Hero ?????????