Maps of the integrated intensity () across W49: HCN 4−3 (top-left); H¹³CN 4−3 (top-right); HCO⁺ 4−3 (middle-left); H¹³CO⁺ 4−3 (middle-right); HNC 4−3 (bottom-left); and HN¹³C 4−3 (bottom-right) line intensities. The main lines are summed over 150 km s^-1, while the ¹³C-substituted lines are summed over 60 km s^-1. The contours show 5, 10, 15, 20, 40 ... 80% of the peak integrated intensity, which is 161 K km s^-1 for HCN, 72 K km s^-1 for H¹³CN, 319 K km s^-1 for HCO⁺, 34 K km s^-1 for H¹³CO⁺, 52 K km s^-1 for HNC, and 4 K km s^-1 for HN¹³C.