Map of CO J = 19−18 (137 μm) integrated intensity with ¹³CO J = 12–11 contours (left). Map of CH⁺J = 3–2 integrated intensity with CO J = 19–18 contours (middle) and OH 84.6 μm with CH⁺J = 3–2 contours (right). All contours are with contour steps of 20% of the peak emission in the Bar starting from 10%, except ¹³CO starting from 30%. The intensities are in units of erg s^-1 cm^-2 sr^-1. The maps are not convolved as the resolutions are similar. Clumps 1 and 3 (Lis & Schilke 2003) are indicated in the figure on the left.