Gas structures in OB cluster-forming region G10.6-0.4. A) IRAM-30 m telescope observations of ¹³CO 2–1, integrated from −3 to 0.6 km s^-1 (Liu et al., in prep.). We omit integrating the blueshifted component in this panel to avoid confusing the gas structures due to blending. B) Color composite image made from the VLA observations of the CS 1–0 line (orange) and the 3.6 cm continuum emission (blue), which were presented in Liu et al. (2011). The deficit of CS 1–0 emission at the center is due to absorption line against the bright UC Hii region. C) Color composite image made from the SMA observations of three CH₃OH transitions, which trace 35 K (red), 60 K (green), and 97 K (blue) upper level energy, respectively. Inset overlays the VLA observations of the optical depth map of the NH₃ (3, 3) satellite hyperfine line, which was reproduced from Sollins & Ho (2005). D) VLA (A-array configuration) image of NH₃ (3, 3) satellite hyperfine line optical depth map (Sollins & Ho 2005).