Subaru IR echelle spectroscopy of Herbig-Haro driving sources.: I.: H2 and [Fe II] emission

We present infrared echelle spectroscopy of three Herbig-Haro (HH) driving sources (SVS 13, B5-IRS 1, and HH 34 IRS) using Subaru IRCS. The large diameter of the telescope and wide spectral coverage of the spectrograph allowed us to detect several H-2 and [Fe II] lines in the Hand K bands. These include H-2 lines arising from v 1-3 and J = 1-11, and [Fe II] lines with upper level energies of E/k (1.1-2.7) x 10(4) K. For all objects the outflow is found to have two velocity components: (1) a high-velocity (-70 to -130 km s(-1)) component (HVC), seen in [Fe II] or H-2 emission and associated with a collimated jet; and (2) a low-velocity (-10 to -30 km s(-1)) component (LVC), which is seen in H-2 emission only and is spatially more compact. Such a kinematic structure resembles optical forbidden emission line outflows associated with classical T Tauri stars, whereas the presence of H-2 emission reflects the low-excitation nature of the outflowing gas close to these protostars. The observed H-2 flux ratios indicate a temperature of (2-3); 10(3) K and a gas density of 10(5) cm(-3) or more, supporting shocks as the heating mechanism. B5-IRS 1 exhibits faint extended emission associated with the H-2-LVC, in which the radial velocity slowly increases with distance from the protostar (by similar to 20 km s(-1) at similar to 500 AU). This is explained as warm molecular gas entrained by an unseen wide-angled wind. The [Fe II] flux ratios indicate electron densities to be similar to 10(4) cm(-3) or greater, similar to forbidden-line outflows associated with classical T Tauri stars. Finally, the kinematic structure of the [Fe II] emission associated with the base of the B5-IRS 1 and HH 34 IRS outflows is shown to support disk-wind models.