Analyzed 1665 and 1667 MHz OH absorption features. Topmost panel: 1665 MHz (black) and 1667 MHz (green) absorption features. Second panel from the top: spectrum converted to optical depth for the 1665 MHz (black) and 1667 MHz (green) transition. Third panel from the top: ¹³CO (1−0) emission in T_mb (data from the GRS survey (l < 60°) and Exeter FCRAO CO survey (l > 60°); Jackson et al. 2006, Mottram & Brunt 2010). The line widths were determined by fitting Gaussian profiles to the 1665 MHz (cyan) and 1667 MHz (orange) absorption, and the ¹³CO (1−0) emission (red). Lowermost panel: H I absorption converted to H I optical depth. Measured bins are denoted by black dots, while we quote lower limits (cyan) for saturated bins. The 1667 MHz transition was observed only towards selected regions and is therefore shown only for a subset of lines-of-sight (see Sect. 2). Theline-of-sight coordinates are given in degrees of Galactic coordinates. The blue shaded area in the lower three panels shows the line integrals. All data were smoothed to a spatial resolution of 46′′.