a) Distribution of the total brightness of the excess component on the contour map of the ¹²CO(J = 1–0) integrated over the velocity range of  + 70 to  + 90 km s^-1. The contours are linearly drawn from 100 to 280 K km s^-1. b) Distribution of the equivalent width of the OH 119 μm absorption line, which is derived by dividing the line flux by the continuum intensity at the central wavenumber. The contour map is the same as that in panel a).