Excitation temperatures T_ex between the upper and lower level of the CO v = 1−0 P(19) transition at 4.844 μm v = 1,J = 19 (upper two panels) and that of the CO v = 4−3 P(20) transition at 4.692 μm v = 4,J = 20 (lower two panels) transitions for the M_disc = 10^-2M_⊙, R_in = 1 AU disc models with (left panels, model 1a) and without (right panels, model 1b) UV pumping. The solid contours (in white or black) in the CO density panels encompass the regions that emit 49% of the fluxes. The black dashed-line contours contain 70% of the fluxes in the vertical direction. The white contours are at gas temperatures of 500 and 1000 K.