Extended Data Fig. 2: The streamer is unrelated to the old inner (radius <3,000 au) envelope or to the outflow emission from the young protostellar system.

Comparison between HC₃N emission tracing the streamer and “chemically old” dense gas in panels a and b, and with the outflow in panel c. Panels a and b show the dense gas traced by N₂H⁺ and N₂D⁺ in the background, with the contours of the chemically fresh material. The streamer is clearly mostly outside the N₂H⁺ and N₂D⁺ emission, and it shows a significantly different morphology to the inner envelope. Panel c shows the outflow emission traced by CO (2-1) in red and blue contours, while the background emission is the HC₃N integrated intensity. This shows that the streamer is unrelated to the outflow interaction. The 50% primary beam response for the N₂H⁺, N₂D⁺, and CO (2-1) observations are shown by the white dotted circle in the left and right panels, respectively. The HC₃N contours levels are drawn at 5, 8, 11, 14 and 17x rms, where rms is 8 mJy beam⁻¹ km s⁻¹. The CO contours levels are drawn at 5, 15, 25, 35 and 45x rms, where rms is 0.2 Jy beam⁻¹ km s⁻¹.