a) Near-infrared H-, Brγ-, and L′-band adaptive optics data coded in blue, green, and red respectively to produce the colour composite of the brightest part of the ultra-compact HII region G333.6-0.2. Blue dashed contours depict 18 μm emission revealing the source IRS 1. H90α recombination-line double-peaked spectra from Fujiyoshi et al. (2006) are overplotted. The numbers below these spectra correspond to the numbering in the original paper (see their Figs. 4 and 5). The thin orange line sketch represents possible margin of the outflow bubble. b) Simulations of a forming massive star system from Krumholz et al. (2009) showing 3000 AU × 3000 AU region at 41 700 years, where the colours represent volume densities. The disk plane and outflow axis are aligned vertically and horizontally.