Transverse velocity shifts in protostellar jets: rotation or velocity asymmetries?

Abstract

Observations of several protostellar jets show systematic differences in radial velocity transverse to the jet propagation direction, which have been interpreted as evidence of rotation in the jets. In this paper we discuss the origin of these velocity shifts, and show that they could be originated by rotation in the flow, or by side to side asymmetries in the shock velocity, which could be due to asymmetries in the jet ejection velocity/density or in the ambient medium. For typical poloidal jet velocities (~ 100-200 km/s), an asymmetry >~ 10% can produce velocity shifts comparable to those observed. We also present three dimensional numerical simulations of rotating, precessing and asymmetric jets, and show that, even though for a given jet there is a clear degeneracy between these effects, a statistical analysis of jets with different inclination angles can help to distinguish between the alternative origins of transverse velocity shifts. Our analysis indicate that side to side velocities asymmetries could represent an important contribution to transverse velocity shifts, being the most important contributor for large jet inclination angles (with respect the the plane of the sky), and can not be neglected when interpreting the observations.

ApJ, in press

References in corpus (11)

• Which jet launching mechanism(s) in TTauri stars?
• A highly-collimated SiO jet in the HH212 protostellar outflow
• T Tauri Jet Physics Resolved Near The Launching Region with the Hubble Space Telescope
• Rotating molecular outflows: the young T Tauri star in CB26
• Submillimeter arcsecond-resolution mapping of the highly collimated protostellar jet HH 211
• 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
• Investigating the transport of angular momentum from young stellar objects: do H2 jets from Class I YSOs rotate?
• Kinematics of the Outflow From The Young Star DG Tau B: Rotation in the vicinities of an optical jet
• A Search for Consistent Jet and Disk Rotation Signatures in RY Tau
• HST-Scale 3D simulations of MHD disc winds : A rotating two-component jet structure
• Curved Herbig-Haro Jets: Simulations and Experiments

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• Laboratory modeling of jets from young stars using plasma focus facilities
• The Asymmetric Bipolar Fe II Jet and H2 Outflow of TMC1A Resolved with JWST's NIRSpec IFU
• Angular momentum in bipolar outflows: dynamical evolutionary model
• A kinematical study of the launching region of the blueshifted HH 46/47 outflow with SINFONI K-band observations
• ALMA discovery of a dual dense probably rotating outflow from a massive young stellar object G18.88MME