Observations of infrared emission lines and radio continuum emission from pre-main-sequence objects

Moderate-resolution observations of the Br-alpha, Br-gamma, Pf-gamma, and H2 v = 1 - 0S(1) emission lines are presented for 16 premain-sequence stars, most of which are low-mass (M less than 5 solar masses) objects. Brackett line emission was detected in nine of 16 objects. H2 emission was confirmed in T Tauri and probably detected in MWC 1080 and L1551 IRS 5. Radio continuum observations at 6 cm are also presented. These results are compared to the predictions of existing models for stellar winds. The results are also compared to the data on molecular outflows. As has been found for higher mass stars, the mass-loss rates derived from CO would imply stronger infrared line and radio continuum emission than were observed. A number of explanations for this discrepancy are discussed, and it is concluded that largely neutral winds provide the most attractive explanation. 69 references.