HUSNG: Facing 3 bet with ATs

[ghettointlectual]

This is the first time that villain has 3 bet me preflop, I have raising about 40% of my hands from the button so far and this opponent has been calling oop most of the time.
Three questions:
1. What range do you put villain on?
2. Do you call here? Why or Why not?
3. If you do decide to call, what is your plan for the rest of the hand? Including Flop, turn and river

Full Tilt Poker
No Limit Holdem Tournament
Blinds: t15/t30
2 players
Converter

Stack sizes:
Hero: t1855
BB: t1145

Pre-flop: (2 players) Hero is SB with T[img]/images/graemlins/heart.gif[/img] A[img]/images/graemlins/heart.gif[/img]
<font color="#cc0000">Hero raises to t60</font>, <font color="#cc0000">BB raises to t180</font>, Hero ?