Position-velocity plots along the direction with PA = 10° towards core A for different species and transitions. The offsets are measured from the dust peak position of core A (see Table 2), positive towards northeast. Contour levels start at 10%, increasing in steps of 10% of the peak: a) 0.87; b) 0.99; c) 0.13; d) 0.64; e) 0.23; f) 0.81; g) 0.76; h) 0.47; i) 0.27; j) 0.30; k) 0.06 and l) 0.34 Jy km s^-1. The white solid line marks the border of the region where emission is expected for an edge-on Keplerian disk of radius (1500 AU) rotating about a 4  M_⊙ central mass.