Villain is unknown. Do you bet this turn? What your play to the push?

Full Tilt No-Limit Hold'em, $2 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP ($195.10)
CO ($197)
Hero ($197)
SB ($152.30)
BB ($200)
UTG ($196.75)

Preflop: Hero is Button with A, T.
3 folds, Hero raises to $8, SB calls $7, 1 fold.

Flop: ($18) 9, 8, 7 (2 players)
SB checks, Hero bets $15, SB calls $15.

Turn: ($48) A (2 players)
SB checks, Hero bets $35, SB raises to $129.3 (All-In), Hero...