Known structure of the environment of the mapped strip. The colors give the total gas column density derived from the Herschel SPIRE and PACS observations. The contours show the line-integrated intensity of ¹³CO 1−0 from the Forgotten Quadrant Survey at levels of 1.5 (white), 3.0 (gray), and 4.5 (black) K km s⁻¹. The mapped area is shown as a red rectangle. The orange circle gives the beam and position of the existing single-pointing [C II] observation.