Extended SiO emission toward the W43-MM1 ridge. SiO(2−1) maps, integrated from 80 km s^-1 to 120 km s^-1, were obtained with the IRAM PdBI a), IRAM 30 m b), and from the merging of both data sets c). Panel a): black contours start at 1.9 Jy/beam km s^-1 with 0.95 Jy/beam km s^-1 steps. Red contours correspond to the Herschel column density map (see Nguyen Luong et al. 2013; Louvet et al. 2014). The contours, going towards the inner parts, are 5 × 10²² cm^-2, 10²³ cm^-2, 1.8 × 10²³ cm^-2, and 3.5 × 10²³ cm^-2. Black rectangles, labeled #1, #2, and #3, indicate the areas where zooms are shown in Fig. 2. Panel b): from Nguyen Luong et al. (2011); black contours start at 2.8 K km s^-1 with 1.2 K km s^-1 steps. Panel c): the black contours start at 0.3 Jy/beam km s^-1 with 1.8 Jy/beam km s^-1 steps. Black ellipses highlight MDCs extracted from the interferometric continuum maps presented in Louvet et al. (2014) and the black cross indicates an extra source, named G, presented by Sridharan et al. (2014). White circles numbered from 1 to 8 indicate the positions of the integrated SiO(2−1) emission spectra presented in Fig. 5.