AKo on button vs. hi-jack raise in the Borgata Friday 50K

[JerseyDP]

Hi all, got a question about a pre-flop play with AKo in above tourney.

At 200-400 50 ante level, I have about 14.5 K in chips.
10 players at the table, with 2 new players just moved in.

Folded around to Hi-Jack, one of the new players who has me covered, no reads on him yet, like his 2nd or 3rd hand at the table.

HJ raises to 1500.
CO folds
I re-raise on the button with AKo to 5k.
SB and BB fold.

HJ asks "How much do I have?". I do nothing, dealer counts my stack, about 9.5K left. HJ thinks for about 30 seconds or so and pushes.

Hero ?