A resolved rotating disk wind from a young T Tauri star in the Bok globule CB26

Abstract

The disk-outflow connection plays a key role in extracting excess angular momentum from a forming protostar. We have previously reported the discovery of a small molecular outflow from the edge-on T Tauri star in the Bok globule CB26 that shows a peculiar velocity pattern, reminiscent of an outflow that corotates with the disk. We report new, high-resolution mm-interferometric observations of CB26 with the aim of revealing the morphology and kinematics of the outflow at the disk-outflow interface. The IRAM PdBI was used to observe CO(2-1) at 1.3mm with a resolution of 0.5". Using a physical model of the disk, which was derived from the dust emission, we employed chemo-dynamical modeling combined with line radiative transfer to constrain kinematic parameters and to construct a model of the CO emission from the disk that allowed us to separate the emission of the disk from that of the outflow. Our observations confirm the disk-wind nature of the rotating molecular outflow from CB26. The new high-resolution data reveal an X-shaped morphology of the CO emission close to the disk, and vertical streaks extending from the disk surface with a small half-opening angle of ~7deg, which can be traced out to vertical heights of ~500au. We interpret this emission as the combination of the disk atmosphere and a well-collimated disk wind, which we trace down to vertical heights of 40au, where it is launched from the surface of the flared disk at radii of 20-45au. The observed CO outflow has a total momentum flux of 1e-5 Msun km/s/yr, which is nearly three orders of magnitude larger than the maximum thrust that can be provided by the luminosity of the central star. We conclude that photoevaporation cannot be the main driving mechanism for this outflow, but it must be predominantly an MHD disk wind. It is thus far the best-resolved rotating disk wind observed to be launched from a circumstellar disk.

arXiv commentAccepted by A&A, 25 pages, 19 figures

References in corpus (55)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The Spitzer Space Telescope Mission
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• The Submillimeter Array
• Gravitational Instabilities in Circumstellar Disks
• The Critical Density and the Effective Excitation Density of Commonly Observed Molecular Dense Gas Tracers
• 2-D Radiative Transfer in Protostellar Envelopes: I. Effects of Geometry on Class I Sources
• Dynamical Masses of T Tauri Stars and Calibration of PMS Evolution
• The unWISE Catalog: Two Billion Infrared Sources from Five Years of WISE Imaging
• Which jet launching mechanism(s) in TTauri stars?
• Magnetic Inhibition of Convection and the Fundamental Properties of Low-Mass Stars. III. A Consistent 10 Myr Age for the Upper Scorpius OB Association
• A study of high velocity molecular outflows with an up-to-date sample
• HST/STIS Spectroscopy of the Optical Outflow from DG Tau: Indications for Rotation in the Initial Jet Channel
• Rotation of Jets from Young Stars: New Clues from the Hubble Space Telescope Imaging Spectrograph
• Locating the Launching Region of T Tauri Winds: The Case of DG Tau
• The earliest phases of star formation - A Herschel key project. The thermal structure of low-mass molecular cloud cores
• Resolved images of a protostellar outflow launched by an extended disk wind
• Disk Imaging Survey of Chemistry with SMA (DISCS): I. Taurus Protoplanetary Disk Data
• Further Indications of Jet Rotation in New Ultraviolet and Optical HST/STIS Spectra
• Disk-Driven Rotating Bipolar Outflow in Orion Source I
• CO destruction in protoplanetary disk midplanes: inside versus outside the CO snow surface
• ALMA discovery of a rotating SO/SO${}_2$ flow in HH212. A possible MHD disk wind?
• Continuum and CO/HCO+ Emission from the Disk Around the T Tauri Star LkCa 15
• Jet rotation: launching region, angular momentum balance and magnetic properties in the bipolar outflow from RW Aur
• Rotation and Outflow motions in the very low-mass Class 0 protostellar system HH 211 at subarcsecond resolution
• Masses and Implications for Ages of Low-Mass Pre-Main Sequence Stars in Taurus and Ophiuchus
• The Role of Magnetic Fields in Protostellar Outflows and Star Formation
• A break in the gas and dust surface density of the disc around the T Tauri star IM Lup
• ALMA reveals a large structured disk and nested rotating outflows in DG Tau B
• Rotating molecular outflows: the young T Tauri star in CB26
• Plateau de Bure Interferometer Observations of the Disk and Outflow of HH30
• Cloudshine: New Light on Dark Clouds
• From infall to rotation around young stellar objects: A transitional phase with a 2000 AU radius contracting disk?
• ALMA detection of the rotating molecular disk wind from the young star HD 163296
• Looking into the hearts of Bok globules: MM and submm continuum images of isolated star-forming cores
• The circumstellar disc in the Bok globule CB 26: Multi-wavelength observations and modelling of the dust disc and envelope
• Rotation in the NGC 1333 IRAS 4C Outflow
• Molecular line radiative transfer in protoplanetary disks: Monte Carlo simulations versus approximate methods
• Evolution of Mass Outflow in Protostars
• Constraining MHD disk winds with ALMA. Apparent rotation signatures and application to HH212
• ALMA observations of the very young Class 0 protostellar system HH 211-mms: a 30-au dusty disk with a disk-wind traced by SO?
• Spitzer and HHT observations of starless cores: masses and environments
• Kinematics of the Outflow From The Young Star DG Tau B: Rotation in the vicinities of an optical jet
• First Detection of Interaction between a Magnetic Disk Wind and an Episodic Jet in a Protostellar System
• A young protoplanetary disk in the Bok globule CB26?
• Dense molecular gas properties on 100 pc scales across the disc of NGC 3627
• High-Resolution NIR Observations of the Circumstellar Disk System in the Bok Globule CB 26
• Snapshot of a magnetohydrodynamic disk wind traced by water maser observations
• Rotating Bullets from A Variable Protostar
• Magneto-Centrifugal Origin for Protostellar Jets Validated through Detection of Radial Flow at the Jet Base
• Distance estimation of some selected small Bok globules
• Pebbles in an Embedded Protostellar Disk: The Case of CB26
• Structure of CB 26 Protoplanetary Disk Derived from Millimeter Dust Continuum Maps
• Angular momentum in bipolar outflows: dynamical evolutionary model

Cited by in corpus (4)

• A kinematical study of the launching region of the blueshifted HH 46/47 outflow with SINFONI K-band observations
• Photoevaporation Can Reproduce Extended ${\mathrm{H}}_2$ Emission from Protoplanetary Disks Imaged by JWST MIRI
• Jet formation in post-AGB binaries: Confronting cold magnetohydrodynamic disc wind wind models with observations
• Dust in the wind of outbursting young stars