Comparison between the v_LSR found for H¹³CO⁺ observations from van’t Hoff et al. (2022) and our H₂CO v_LSR results. Left: Central velocities obtained through the Gaussian fit to H¹³CO⁺ observations from van’t Hoff et al. (2022). The black ellipse represents the beam size. The black contour indicates the area covered by the H₂CO blueshifted cluster found using DBSCAN. The black star represents the position of B5-IRS1. Right: KDE of the difference between the central velocities of H₂CO and H¹³CO⁺ emission. The dotted line shows the one-to-one relation, and the solid line shows the same relation but displaced by 0.02 km s⁻¹