Upper left: integrated intensities of HNCO 5₀₅ − 4₀₄ vs. HC₃N 10−9; upper right: linewidth of HNCO 5₀₅ − 4₀₄ vs. HC₃N 10−9; lower left: size of HNCO 5₀₅ − 4₀₄ vs. HC₃N 10−9. The dotted line has a slop of 1; lower right: LSR velocity difference between HNCO 5₀₅ − 4₀₄ and HC₃N 10−9 vs. LSR velocity difference between HNCO 5₀₅ − 4₀₄ and C¹⁸O 1−0. The source names were also labeled in the figure.