RRL clumps over RRL, HNC 1-0, and far-infrared maps. Top left: three groups of RRL clumps – within the Sagittarius-Carina arm (red), AqS (green), and off-arm near the Sagittarius-Carina arm (blue) – overlaid on a velocity-integrated intensity map of RRL from 0 to 120 km s⁻¹. The beam size of FAST ($4_{.}^{\mathrm{\prime }}7$) is presented as circle in the bottom-left corner. Top right: contour of the velocity-integrated intensity map of HNC 1-0 from 53 to 62 km s⁻¹ on the RRL map. The contour levels are 3.0, 6.0, 9.0, 12.0, 15.0, 18.0, 21.0, 24.0, 27.0, and 30.0σ, where σ is 0.22 K km s⁻¹. The beam of the Taeduk Radio Astronomy Observatory (TRAO) 14 m telescope for HNC 1-0 (57″) is presented as a small circle within that of the FAST beam. Bottom left: same as the top right but with 70 μm emission instead of HNC 1-0. The contour levels are 5, 12.5, 25, 125, 250, 500, and 1000 σ, where σ is 0.04 Jy pixel⁻¹. The beam size of 70 μm (6″) emission is presented within the FAST beam. Bottom right: same as top right and bottom left, but with 160 μm emission. The contour levels are 5, 10, 50, 100, 200 and 400σ, where σ is 0.1 Jy pixel⁻¹. The beam size of 160 μm (12′) emission is shown within the FAST beam.