They also reported the H$_{2}$ shell as an expanding shell. Using the [*Spitzer*]{} 3.6–8.0 $\mu$m images, the infrared emission has been observed toward the H$_{2}$ shell [@jiang13], which is now referred to as an infrared shell in the present work.

Dust continuum, CS, and NH$_{3}$ emissions were observed about 1$'$.5 away from the evolved cluster or the infrared shell [@verdes89; @pastor91; @torrelles92b; @klein05; @lee11; @fontani12; @jiang13]. A few H$_{2}$O masers and an H[ii]{} region were reported toward the dense NH$_{3}$ core [@torrelles92b]. Using the VLA 3.6 cm map, @torrelles92b suggested that the H[ii]{} region is powered by a ZAMS B3 star. @snell88 reported a bipolar CO outflow, which was centered on the dense NH$_{3}$ core [see also @zhang05]. On the basis of previously published results in AFGL 5157, a summary figure containing different observed features (i.e., infrared shell, dense core, and H[ii]{} region) is presented in Figure \[fig1\]a. Figure \[fig1\]a shows the [*Spitzer*]{} 3.6 $\mu$m image (size $\sim$2.7 pc $\times$ 2.7 pc) overlaid with the SCUBA 850 $\mu$m dust continuum emission contours [@difrancesco08; @jiang13]. Three peaks seen in the 850 $\mu$m dust continuum map (i.e., peak1, peak2, and peak3) are also highlighted in the figure, which may trace the dense 