Top: stellar LOSV, fitted LOSV model and the subtracted residual in units of [km s^-1]. Bottom: H₂(1−0)S(1) LOSV, fitted LOSV model and the subtracted residual overlayed with contours of the EW map of H₂(1−0)S(1) in units of [km s^-1]. The EW map was overlayed to display the nuclear spiral onto the residual velocity field of the gas. The straight lines denote the orientation of the major and minor rotation axis as determined by the LOSV model. For more details, see Sect. 3.6.