Sgr B2 (M): searches for NH⁺ and p-NH show no clear detections at the source molecular cloud velocities 58–69 km s^-1 (marked in blue) or the line-of-sight absorption between −140 and 27 km s^-1 (marked in red). Possible weak NH⁺ absorption from the molecular cloud is blended with the stronger CH₂NH absorption. Para-NH is tentatively detected from the source molecular cloud, however, at V_LSR = 19 km s^-1. All emission lines originate in the Sgr B2 (M) molecular cloud.