Five Herbig-Haro objects SOFIA/FIFI-LS images

Strong [OI]63um emission is detected at the driving sources HH111IRS, HH34IRS, SVS13, as well as at the bow shock region, HH7. The detection of the [OI]63um line at HH26A and HH8/HH10 can be attributed to jet deflection regions. The far-infrared counterpart of the optical jet is detected in [OI]63um only for HH111, but not for HH34.

We interpret the [OI]63um emission at HH111IRS, HH34IRS, and SVS13 to be coming primarily from a decelerated wind shock, whereas multiple internal shocks within the HH111 jet may cause most of the [O I]63um emission seen there. At HH30, no [O I]63um,145um was detected. The [OI]145um line detection is at noise level almost everywhere in our obtained maps.

The observed outflow rates of our Class I sample are to the order of dM/dt_jet_~10^-6^M_{sun}_/yr, if proper shock conditions prevail. Independent calculations connecting the [OI]63um line luminosity and observable jet parameters with the mass-loss rate are consistent with the applied shock model and lead to similar mass-loss rates. Wediscuss applicability and caveats of both methods.

High-quality spectroscopic [OI]63um maps of protostellar outflows at the jet driving source potentially allow a clear determination of the mass ejection rate.