[10NL] AQo IP facing river jam

Villain is complete unknown.

PokerStars - $0.10 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

UTG: $6.64
MP: $10.00
CO: $32.54
Hero (BTN): $10.00
SB: $8.23
BB: $10.00

SB posts SB $0.05, BB posts BB $0.10

Pre Flop: (pot: $0.15) Hero has Q A

UTG calls $0.10, fold, CO calls $0.10, Hero raises to $0.50, SB calls $0.45, fold, UTG calls $0.40, fold

Flop: ($1.70, 3 players) A 2 6
SB checks, UTG checks, Hero bets $0.85, fold, UTG calls $0.85

Turn: ($3.40, 2 players) 5
UTG checks, Hero bets $2.00, UTG calls $2.00

River: ($7.40, 2 players) 9
UTG bets $3.29 and is all-in, Hero ???

Hand seems fairly standard up until river. Thoughts on the jam and what hero should do?