H_2_O spectra of 29 nearby Class 0/I protostars

Water is the ideal tracer of these effects because it is present in high abundance for the conditions expected in various parts of the protostar, particularly the outflow. We constrain and quantify the physical conditions probed by water in the outflow-jet system for Class 0 and I sources.

We present velocity-resolved Herschel HIFI spectra of multiple water-transitions observed towards 29 nearby Class 0/I protostars as part of the WISH guaranteed time key programme. The lines are decomposed into different Gaussian components, with each component related to one of three parts of the protostellar system; quiescent envelope, cavity shock and spot shocks in the jet and at the base of the outflow. We then use non-LTE radex models to constrain the excitation conditions present in the two outflow-related components.