N₂H⁺(1−0) (diazenylium) integrated intensity map between −75 and +110 km s^-1of the Mopra observations by Jones et al. (2012). The spatial resolution of the map is 44′′ with 3.6 km s^-1 spectral resolution. The first contour is located at ~1 K km s^-1 , equivalent to 5 × σ with σ the typical noise of the map. The contour increment is 5 K km s^-1. The solid straight line shows the position of the Galactic plane at b = 0°; the marks denote a few Galactic longitude values for orientation. The area is covered by the Herschel-HIFI observations.