Oral Presentation

Optical [Ne III] Jet from DG Tau with VLT/X-Shooter Spectra

Chun-Fan Liu (ASIAA/NTU/TIARA), Hsien Shang (ASIAA/TIARA), Gregory J. Herczeg (KIAA/PKU), Frederick M. Walter (SBU)

We present optical long-slit spectra of the blueshifted jet of DG Tau obtained with the Very Large Telescope (VLT) X-Shooter spectrograph. DG Tau is a flat-spectrum T Tauri star driving a bright jet that emits from X-ray to radio wavelengths. The doubly ionized neon forbidden line [Ne III] 3869 was discovered in the inner 3" microjet and 2 outer knots located at 7" and 13" from the star, respectively. The existence of doubly ionized neon along the jet suggests high ionization maintained in the jet, which may be attributed to the frozen-in ionization of hard X-ray irradiation from star-disk interaction near the launching region and shock ionization in the jet. Comparing with other optical line emission and extended soft X-ray emission along the jet axis, we aim at investigating the outflow history of DG Tau.