VLT VIMOS tomography of the Hα and [N II] λλ6548,6584 emission lines of FH Ser. Each velocity channel has a width of 82 km s⁻¹, i.e., three spectral channels. The white, cyan, and red labels correspond to LSR velocities of the Hα, [N II] λ6548, and [N II] λ6584 emission lines, respectively. The location of the central star is marked by a red plus sign that serves as a fiducial point in all channel maps. In all maps, north is up and east is to the left. See the text for further details of the spectral and spatial extent of each emission line.