“…One can see that the concentration of both N 2 and O 2 increases dramatically as soon as the temperature diminishes. The high concentrations of molecular nitrogen after the front will produce intense fluorescence emission lines from the second positive system of N 2 at 295, 310, 335, and 357 nm as soon as the temperature is higher than 6000 K [ Capitelli et al , ; Losev and Yarygina , ; Becker et al , ; Chauveau et al , ; Laux et al , ; Chauveau et al , ], which occurs closely to r = 3 cm (Figures and ). Between the hot core and the shock front, the concentrations of OH, NO, and NO 2 are much larger due to lower temperatures.…”