A MUSE Spectro-imaging Study of the Th 28 Jet: Precession in the Inner Jet

Abstract

Context: Th 28 is a Classical T Tauri star in the Lupus 3 cloud which drives an extended bipolar jet. Previous studies of the inner jet identified signatures of rotation around the outflow axis, a key result for theories of jet launching. Thus this is an important source in which to investigate the poorly understood jet launching mechanism. We investigate the morphology and kinematics of the Th 28 micro-jets with the aim of characterizing their structure and outflow activity, using optical integral-field spectroscopy observations obtained with VLT/MUSE. We use spectro-imaging and position-velocity maps to investigate the kinematic and morphological features of the jet, and obtain a catalogue of emission lines in which the jet is visible. A Lucy-Richardson deconvolution procedure is used to differentiate the structure of the inner micro-jet region. Spatial profiles extracted perpendicular to the jet axis are fitted to investigate the jet width, opening angle and the evolution of the jet axis. We confirm the previously identified knot HHW${}_2$ within the red-shifted jet and identify three additional knots in each lobe for the first time. We also find [O III]$\lambda$5007 emission from the blue-shifted micro-jet including the knot closest to the star. Proper motions for the innermost knots on each side are estimated and we show that new knots are ejected on an approximate timescale of 10-15 years. The jet axis centroids show a point-symmetric wiggle within the inner portion of both micro-jets indicating precession. We use the jet shape to measure a precession period of 8 years, with a half-opening angle < 0.6${}^{\circ }$. This may provide an alternative explanation for the rotation signatures previously reported. We find the jet shape to be compatible with precession due to a brown dwarf companion orbiting at a separation $\le$ 0.3 au.

Accepted by Astronomy & Astrophysics; 21 pages, 23 figures

References in corpus (9)

• The MUSE second-generation VLT instrument
• The Data Processing Pipeline for the MUSE Instrument
• Proper Motions of the Jets in the Region of HH 30 and HL/XZ Tau. Evidence for a Binary Exciting Source of the HH 30 Jet
• First image of the L1157 molecular jet by the CALYPSO IRAM-PdBI survey
• ALMA observations of the Th 28 protostellar disk - A new example of counter-rotation between disk and optical jet
• Launching the asymmetric bipolar jet of DO Tau
• Jets from young stars and brown dwarfs
• Revealing Ionization Conditions of Sz 102 with Spatially Resolved [Ne III] Microjets
• Discovery of a jet from the single HAe/Be star HD 100546

Cited by in corpus (12)

• The He I $\lambda$10830 $\mathring{A}$ line as a probe of winds and accretion in young stars in Lupus and Upper Scorpius
• The Asymmetric Bipolar Fe II Jet and H2 Outflow of TMC1A Resolved with JWST's NIRSpec IFU
• A spectacular jet from the bright 244-440 Orion proplyd: the MUSE NFM view
• A kinematical study of the launching region of the blueshifted HH 46/47 outflow with SINFONI K-band observations
• Study of the bipolar jet of the YSO Th 28 with VLT/SINFONI: Jet morphology and H${}_2$ emission
• The Morphology of the HD 163296 jet as a window on its planetary system
• Optical Forbidden Emission Line Spectro-astrometry of T CrA: Evidence for a Multiple System and Multiple Jets
• HOPS 361-C's Jet Decelerating and Precessing Through NGC 2071 IR
• Protostellar Outflows: a window to the past
• Forbidden Emission Line spectro-imaging of the RU Lupi jet and Low Velocity Component
• Investigating the asymmetry of young stellar outflows: Combined MUSE-X-shooter study of the Th 28 jet
• The accretion-ejection connection in the asymmetric Th 28 jet revealed by MUSE-NFM