HDO 225 GHz (black contours) and HDO 241 GHz (green-dashed contours) integrated map observed with the SMA. The contour levels are from 3σ by steps of 6σ, with 1σ = 1.5 Jy beam^-1. The red crosses indicate the peak of the 24 GHz free-free continuum emission (A, B, and C positions from Heaton et al. 1989) and the peak (maximum pixel) of the 1.3 mm continuum observed with the SMA is shown with the dark blue cross. The blue ellipse indicates the beam size.