Investigating the asymmetry of young stellar outflows: A combined MUSE-X-Shooter study of the Th 28 jet

This record contains supplementary tables and figures for the article 'Investigating the asymmetry of young stellar outflows: A combined MUSE-X-Shooter study of the Th 28 jet' by A. Murphy, E. T. Whelan, F. Bacciotti, D. Coffey, F. Comeron, J. Eisloffel, B. Nisini, S. Antoniucci, J. M. Alcala and T. P. Ray, accepted for publication by Astronomy & Astrophysics.

Abstract:

Characterising stellar jet asymmetries is key to providing robust constraints for jet launching models, and hence to understanding the underlying mechanisms of jet launching. This study aims to characterise the asymmetric properties of the bipolar jet from the Classical T Tauri Star Th 28. We combine data from integral field spectroscopy with VLT/MUSE and high-resolution spectra from VLT/X-Shooter to map optical emission line ratios in both jet lobes. We carry out a diagnostic analysis of these ratios to compare the density, electron temperature, and ionisation fraction within both lobes. The mass accretion rate is derived from the emission lines at the source, and compared with the mass outflow rate derived in both lobes using the estimated densities and measured [O I]λ6300 and [S II]λ6731 luminosities. The blue-shifted jet shows a significantly higher electron temperature and moderately higher ionisation fraction than the red-shifted jet. In contrast to previous studies we also estimate higher densities n H in the blue-shifted jet by a factor ∼2. These asymmetries are traced to within 1′′ (160 au) of the source in the line ratio maps. We find Ṁacc = 2.4 × 10^−7 M⊙ yr ^−1 , with an estimated obscuration factor of ∼54 due to grey scattering around the star. Estimated values of Ṁout range between 0.66 – 13.7 × 10^−9 M⊙ yr^−1 in the blue-shifted jet and 5-9 × 10^−9 M⊙ yr^−1 in the red-shifted jet. The emission line maps and diagnostic results suggest that the jet asymmetries originate close to the source and are likely intrinsic to the jet. Furthermore, the combined dataset allows access to a broad array of accretion tracers. This in turn enables a more accurate estimation of the mass accretion rate, revealing Ṁacc higher by a factor > 350 than would otherwise be determined.

Summary of supplemental material:

Table 1: Emission lines detected in X-shooter observations of the jet. Fluxes are measured from the red-shifted jet lobe.

Tables 2 and 3: Mass accretion rates measured from MUSE and X-Shooter observations of Th 28, respectively, assuming an on-source extinction of 2.5 mags.

Tables 4 and 5: As in Tables 2 and 3, for an on-source extinction of 1.26 mags.

Figures 1-4: Position-velocity maps of detected emission lines from the UV and VIS arms of the X-shooter observations.

Figure 5: Accretion luminosities measured from MUSE and X-Shooter data, before and after correction for on-source obscuration. Left and right panels show the corresponding values if the fluxes are corrected for a wavelength-dependent extinction of 2.5 and 1.26 mags, respectively.