The First X-shooter Observations of Jets from Young Stars

Abstract

We present the first pilot study of jets from young stars conducted with X-shooter, on ESO/VLT. As it offers simultaneous, high quality spectra in the range 300-2500 nm X-shooter is uniquely important for spectral diagnostics in jet studies. We chose to probe the accretion/ejection mechanisms at low stellar masses examining two targets with well resolved continuous jets lying on the plane of the sky, ESO-HA 574 in Chamaleon I, and Par-Lup3-4 in Lupus III. The mass of the latter is close to the sub-stellar boundary (Mstar=0.13 Msun). A large number of emission lines probing regions of different excitation are identified, position-velocity diagrams are presented and mass outflow/accretion rates are estimated. Comparison between the two objects is striking. ESO-HA 574 is a weakly accreting star for which we estimate a mass accretion rate of log(\dot{Macc}) = -10.8 \pm 0.5 (in Msun/yr), yet it drives a powerful jet with \dot{Mout} ~ 1.5-2.7 10^-9 Msun/yr. These values can be reconciled with a magneto-centrifugal jet acceleration mechanism only assuming that the presence of the edge-on disk severely depresses the luminosity of the accretion tracers. In comparison Par-Lup3-4 with stronger mass accretion (log(\dot{Macc}) = -9.1 \pm 0.4 Msun/yr), drives a low excitation jet with about \dot{Mout} ~ 3.2 10^-10 Msun/yr in both lobes. Despite the low stellar mass, \dot{Mout} / \dot{Macc} for Par-Lup3-4 is at the upper limit of the range usually measured for young objects, but still compatible with a steady magneto-centrifugal wind scenario if all uncertainties are considered.

20 pages, 4 figures, accepted by ApJ Letters

References in corpus (11)

• UV excess measures of accretion onto young very low-mass stars and brown dwarfs
• Which jet launching mechanism(s) in TTauri stars?
• The Stellar Population of the Chamaeleon I Star-Forming Region
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. XI. Lupus Observed With IRAC and MIPS
• Recipes for stellar jets: results of combined optical/infrared diagnostics
• Spatially Resolved Molecular Hydrogen Emission in the Inner 200AU Environments of Classical T Tauri Stars
• Modeling T Tauri Winds from He I 10830 Profiles
• Tracing kinematical and physical asymmetries in the jet from DG Tau B
• The 2008 Outburst in the Young Stellar System Z CMa: The First Detection of Twin Jets
• Multi-wavelength study of the disk around the very low-mass star Par-Lup3-4
• Tracing the origins of permitted emission lines in RU Lupi down to AU scales

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