Schematic image of DK Cha based on its emission of SO and SO₂ (Fig. 8). The major gas components that can be seen from the observed data (Fig. 8) are labeled. The black ellipse marks the disk traced by continuum that cannot be fully resolved. The direction of rotation is unknown, and we suggest a clockwise rotation based on the velocity distributions along the streamers and near the disk traced by SO and CO (2-1) (Figs. 8 and 11; see also Sect. 3.2.5). The green ellipse is the assumed disk-like inner envelope, which has strong interaction with the streamers that fall onto it (S1, S2, and S3). The interaction contributes to the enhancement of SO/SO₂ emission on the segment (P1) and spot (P2) at the inner envelope (Sect. 3.2).