Abstract
In this paper a comprehensive analysis of VLT / X-Shooter observations of two jet systems, namely ESO-H$\alpha$ 574 a K8 classical T Tauri star and Par-Lup 3-4 a very low mass (0.13~\Msun) M5 star, is presented. Both stars are known to have near-edge on accretion disks. A summary of these first X-shooter observations of jets was given in a 2011 letter. The new results outlined here include flux tables of identified emission lines, information on the morphology, kinematics and physical conditions of both jets and, updated estimates of $\dot{M}_{out}$ / $\dot{M}_{acc}$. Asymmetries in the \eso flow are investigated while the \para jet is much more symmetric. The density, temperature, and therefore origin of the gas traced by the Balmer lines are investigated from the Balmer decrements and results suggest an origin in a jet for \eso while for \para the temperature and density are consistent with an accretion flow. $\dot{M}_{acc}$ is estimated from the luminosity of various accretion tracers. For both targets, new luminosity relationships and a re-evaluation of the effect of reddening and grey extinction (due to the edge-on disks) allows for substantial improvements on previous estimates of $\dot{M}_{acc}$. It is found that log($\dot{M}_{acc}$) = -9.15 $\pm$ 0.45~\Msun yr$^{-1}$ and -9.30 $\pm$ 0.27~\Msun yr$^{-1}$ for \eso and \para respectively. Additionally, the physical conditions in the jets (electron density, electron temperature, and ionisation) are probed using various line ratios and compared with previous determinations from iron lines. The results are combined with the luminosity of the [SII]$\lambda$6731 line to derive $\dot{M}_{out}$ through a calculation of the gas emissivity based on a 5-level atom model.
Highlights
The mass outflow phase is a key stage in the star formation process
The density, temperature, and origin of the gas traced by the Balmer lines are investigated from the Balmer decrements and results suggest an origin in a jet for European Southern Observatory (ESO)-Hα 574 while for Par-Lup 3-4 the temperature and density are consistent with an accretion flow
Par-Lup 3-4 has a spectrum which is typical of a young very low mass stars (VLMS), in that all the usual accretion tracers are found while the jet is detected in only a handful of lines, e.g. [OI]λ6300, [SII]λ6731 (Whelan et al 2009)
Summary
The mass outflow phase is a key stage in the star formation process. Protostellar jets (fast, collimated outflows) are an important manifestation of the outflow phenomenon and it is generally. In Bacciotti et al (2011), outflow and accretion tracers present in the spectra were examined, the effect of extinction by an edgeon disk was discussed, and first estimates of Macc and the jet parameters ne and Mout were given. This analysis was tentative, and is expanded and improved on here with new up-to-date procedures. The study of Par-Lup 3-4 was relevant to the question of the applicability of jet launching models at the lowest masses and one of the particular aims of the work presented here was to overcome difficulties with previous estimates of Mout/Macc in Par-Lup 3-4. The origin of the permitted emission in both sources is explored by examining their Balmer decrements (see Sect. 4.6)
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