Integrated intensity maps of CH₃ CCH observed towards B68, L1521E (Nagy et al. 2019), and L1544 (Spezzano et al. 2017). The solid line contours indicate the 3σ level of the integrated intensity for B68 and L1521E, and the 6σ level for L1544. The dashed line contours represent 90%, 50%, and 30% of the H₂ column density peak derived from Herschel maps (Spezzano et al. 2020). The white circle in the bottom-left corner indicates the beam size of the IRAM 30m telescope (32").