The night-sky spectra for the OH-suppressed observations (red), and the control fibre without OH suppression (blue). The two plots are of the same data; the bottom one has been logged to make the interline regions visible. The pairs of vertical black lines show the OH lines from the Q1(3.5) and Q1(4.5) rotational lines in the 3-1, 4-2 and 5-3 vibrational transitions (from left to right). The green line shows the O2 a-X v=0-1 vibrational line.