NL50: Putting people on ranges when they call 3bet PF

[gregorio]

Perhaps this is a better example of my confusion

Preflop: Hero in SB with A[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/heart.gif[/img]
Button raises 4BB, Hero in SB raises to 14BB, Button calls

Flop: (28BB) J[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/club.gif[/img] 5[img]/images/graemlins/diamond.gif[/img]
Hero bets 18BB, Button calls

How can I be ahead here after they call. They must have 99, JJ+ or AJ to call here. But often they don't. What is their range. Is it just 99+, AJ and 25% WTF?