Position–velocity diagrams of HH 1042 (top) and HH 1043 (bottom) for various lines, as labeled. The absolute flux scale is logarithmic. The underlying stellar continuum (at distance = 0′′), where present, was subtracted using a Gaussian fit. The ambient cloud produces emission in most lines at zero velocity (by definition) over the full length of the slit. In most lines the blue lobe of the HH 1042 jet is very prominent, while the red lobe suffers from extinction. The measured radial velocities in HH 1043 are significantly lower than those in HH 1042.