Velocity-channel maps of the ¹³CO 3–2 emission toward Cha-MMS1. The cross marks the peak continuum position. The central velocity is shown in km s⁻¹ in the upper left corner. The contour steps are − 6σ, − 3σ, 3σ, 6σ, 12σ, 24σ, and 48σ with σ = 4.7 mJy beam⁻¹. The light blue contours represent the negative levels. The primary beam (black circle) and the synthesized beam (red ellipse) are shown in the upper left panel. The maps are not corrected for primary beam attenuation. The systemic velocity is v_sys = 4.43 km s⁻¹ (Belloche et al. 2006).