SiO column density and abundance versus H₂ column density and L_bol/M_dump, respectively. Upper: molecular hydrogen column density versus SiO column density. Black diagonal dot-lines indicate SiO abundance on the y-axis relative to N(H₂), with its values labeled. Lower: comparison between L_bol/M_clump and SiO abundance. Uncertainties depending on T_ex are indicated with error bars for both the plots.