Complementary distribution of N68a and N68b. The RGB-composite map with its R, G, and B colors encoded by N65b, Spitzer − IRAC 8.0 μm, and N65a, respectively. The solid blue contours indicate the ¹³CO integrated-intensity map of N65a, while the dashed red contours indicate that of N65b. The contour levels in the figure are drawn from 9 (3σ) to 45 K km s⁻¹ in steps of 6 K km s⁻¹.