(color online) Temporal intensity distributions along panels (a), (c), (e) propagating and panels (b), (d), (f) radical directions of pulses passing through 1-m-long argon gas-filled HCFs: (a), (b) without chirps at 500 mbar, (c), (d) with a positive chirp to 60 fs at 1.3 bar, and (e), (f) with a positive chirp to 100 fs at 3 bar.