870 μm continuum emission (color scale) and ¹³CO 1–0 line spectra observed toward a few bright 870 μm continuum peaks. In the panels showing spectra taken toward the numbered positions in the image, the main velocity range of W43 (80−110   km   s^-1) is indicated with gray filling, while dashed lines mark the NH₃ peak velocities (Wienen et al., in prep.). In the image, the two main bridges identified between W43-main and South (blue bars) are outlined by red curves, which are continuous when they correspond to ¹³CO 1–0 filaments clearly identified by Motte et al. (in prep.) and dashed or dotted for more tentative connections. W43-MM1, W43-MM2, and G29.96-0.2 are indicated as reference points. The white circles indicate W43-main and W43-south, their areas are used to integrate the spectra of Fig. 2.