2018A&A...610L..19W

In this Letter a near-infrared integral field study of a proto-brown dwarf candidate is presented. A ∼0.5" blue-shifted outflow is detected in both H₂ and [FeII] lines at V_sys=(-35±2)km/s and V_sys=(-51±5)km/s respectively. In addition, slower (~±10km/s) H₂ emission is detected out to <5.4", in the direction of both the blue and red-shifted outflow lobes but along a different position angle to the more compact faster emission. It is argued that the more compact emission is a jet and the extended H₂ emission is tracing a cavity. The source extinction is estimated at A_v=18±1mag and the outflow extinction at A_v=9±0.4mag. The H₂ outflow temperature is calculated to be 1422±255K and the electron density of the [FeII] outflow is measured at ∼10000cm^–3. Furthermore, the mass outflow rate is estimated at M_out[H2]=3.8x10^–10M_☉/yr and M_out[FeII]=1x10^–8M_☉/yr. M_out[FeII] takes a Fe depletion of ∼88% into account. The depletion is investigated using the ratio of the [FeII] 1.257µm and [PII] 1.188µm lines. Using the Paβ and Brγ lines and a range in stellar mass and radius M_acc is calculated to be (3-10)x10^–8M_☉/yr. Comparing these rates puts the jet efficiency in line with predictions of magneto-centrifugal models of jet launching in low mass protostars. This is a further case of a brown dwarf outflow exhibiting analogous properties to protostellar jets.