AA facing an all-in vs short w/ a cold caller

[PhatPots]

5/5 NL live

CO is suppose to be some what of a loose player. Other players have made several comments when he sat down "Oh finally we are going to see some action, etc. etc."

Button is an older man who has bet big several times, he has 3-bet preflop 3 times so far. I doubled him up (stupidly) several hands ago when he had a set of Queens and I had an underpair trying thinking he missed. He now has 450.

We are 10 handed and have been sitting for about 2 hours

CO has $100
Button has $480
Hero has $900

Preflop: Hero is UTG with A [img]/images/graemlins/spade.gif[/img] A [img]/images/graemlins/heart.gif[/img]
<font color="red">Hero raises to $25</font> , CO calls, Button calls, blinds fold

Flop: J [img]/images/graemlins/club.gif[/img] 9 [img]/images/graemlins/heart.gif[/img] 4 [img]/images/graemlins/diamond.gif[/img]
<font color="red">Hero bets $45 </font>, <font color="red"> CO goes all-in ($100),</font>, Button calls, <font color="red">Hero raises to $280, Button raises all-in ($195 more)</font>, Hero?

How do we interpret this? Set? J9? AJ and he is fed up? Could be QQ?
I have to think that a re-raise in this situation is best once he cold calls. I don't think the $195 is enough to fold given the size of the pot

Thoughts please