Velocity-integrated intensity maps and spatial averaged spectra of C₄H 9–8, c-C₃H₂ 2–1, H¹³CO⁺ 1–0, and H42α. The source names are presented in the maps and spectra. The grey scale colour at the right is in units of K km s⁻¹. (a and b) Velocity-integrated intensity maps of G015.03–00.67, where panel a shows C₄H 9–8 (red contours) overlaid on c-C₃H₂ 2–1 (blue contours and grey scale) and panel b shows H42α (magenta contours) overlaid on H¹³CO⁺ 1–0 (black contours and grey scale). The excitation peak of H42α is marked with a magenta five-pointed star in panel a–d Spectra of C₄H at 85 672.5793 MHz and c-C₃H₂ at 85 338.8940 MHz in the green and cyan box of G015.03-00.67. The detailed mapping information of all sources for C₄H 9–8, c-C₃H₂ 2–1 and H¹³CO⁺ 1–0 are listed in Table B.3.