value less than one (i.e., $<$ 1.0) then one may notice significant self-absorption in the direction of the [*Herschel*]{} clump “D", which is an area between the [*Herschel*]{} clump “E" (or the sub-mm peak3) and the infrared shell.

Figures \[fig5\] and \[fig6\] display the integrated $^{12}$CO and $^{13}$CO velocity channel maps from $-$23 to $-$14 km s$^{-1}$, respectively. Each velocity channel map is produced by integrating the emission over 1 km s$^{-1}$ velocity interval. The location of the filamentary feature is also marked in both the channel maps. The velocity channel maps also suggest the presence of two velocity components (see panels at \[$-$17, $-$16\] and \[$-$20, $-$19\] km s$^{-1}$ in Figures \[fig5\] and \[fig6\]). Figures \[fig7\]a and \[fig7\]b present the first moment maps of $^{12}$CO and $^{13}$CO, respectively. The moment map is known to depict the intensity-weighted mean velocity of the emitting gas. Figure \[fig7\]c displays a color-composite image of AFGL 5157 with the $^{13}$CO maps at \[$-$17, $-$16\] and \[$-$20, $-$19\] km s$^{-1}$ in red and green, respectively. The filamentary feature observed in the [*Herschel*]{} column density map is also highlighted in Figures \[fig7\]a, \[fig7\]b, and \[fig7\]c. It seems that this color-composite image reproduces the velocity field as 