Adaptive Optics Spectroscopy of the [Fe<scp>ii</scp>] Outflow from DG Tauri

Pyo, Tae‐Soo; Kobayashi, Naoto; Hayashi, Masahiko; Terada, Hiroshi; Goto, Miwa; Takami, Hideki; Takato, Naruhisa; Gäessler, Wolfgang; Usuda, Tomonori; Yamashita, Takuya; Tokunaga, A. T.; Hayano, Yutaka; Kamata, Yukiko; Iye, Masanori; Minowa, Yosuke

doi:10.1086/374966

Cited by 101 publications

(221 citation statements)

References 44 publications

Supporting

Mentioning

193

Contrasting

Order By: Relevance

“…Thus this result may indicate an interaction of a low-velocity disc-wind with the source envelope as the possible origin of the LVC in Class I jets. The large extent of the LVC is at variance with the PVDs of most of the CTT, where the LVC is usually confined within ∼200 AU from the source (Pyo et al 2003(Pyo et al , 2006.…”

Section: Discussionmentioning

confidence: 99%

IR diagnostics of embedded jets: kinematics and physical characteristics of the HH46-47 jet

Lopez

Nisini

Eislöffel

et al. 2010

A&A

View full text Add to dashboard Cite

Context. We present an analysis of the kinematics and physical properties of the Class I driven jet HH46-47 based on IR medium and low resolution spectroscopy obtained with ISAAC on VLT. Aims. Our aim is to study the gas physics as a function of the velocity and distance from the source and to compare the results with similar studies performed on other Class I and classical T Tauri jets as well as with existing models for the jet formation and excitation. have been used to derive physical parameters such as electron density, H 2 temperature, iron gas-phase abundance and mass flux. Methods[Fe ii] 1.644 μm and H 2 2.122 μm position velocity diagrams (PVDs) have been additionally constructed to study the kinematics of both the atomic and molecular gas. Results. Within 1000-2000 AU from the source the atomic gas presents a wide range of radial velocities, from ∼-230 km s −1 to ∼100 km s −1 . Only the gas component at the highest velocity (high velocity component, HVC) survives at large distances. The H 2 shows only a single velocity component at almost zero velocity close to the source while it reaches higer velocities (up to ∼95 km s −1 ) further downstream. Electron densities (n e ) and mass ejection fluxes (Ṁ jet ) have been separately measured for the HVC and for the component at lower velocity (LVC) from the [Fe ii] lines. n e increases with decreasing velocities with an average value of ∼ 6000 cm −3 for the LVC and ∼4000 cm −3 for the HVC, while the opposite occurs forṀ jet which is ∼0.5−2 × 10 −7 M yr −1 and ∼0.5−3.6 × 10 −8 M yr −1 for the HVC and LVC, respectively. The mass flux carried out by the molecular component, measured from the H 2 lines flux, is ∼4 × 10 −9 M yr −1 . We have estimated that the Fe gas phase abundance is significantly lower than the solar value, with ∼88% of iron still depleted onto dust grains in the internal jet region. This fraction decreases to ∼58%, in the external knots. Conclusions. Many of the derived properties of the HH46-47 jet are common to jets from young stellar objects (YSOs) in different evolutionary states. The derived densities and mass flux values are typical of Class I objects or very active T Tauri stars. However, the spatial extent of the LVC and the velocity dependence of the electron density have been so far observed only in another Class I jet, the HH34 jet, and are not explained by the current models of jet launching.

show abstract

Section: Discussionmentioning

confidence: 99%

IR diagnostics of embedded jets: kinematics and physical characteristics of the HH46-47 jet

Lopez

Nisini

Eislöffel

et al. 2010

A&A

View full text Add to dashboard Cite

show abstract

“…A dual origin in a magnetospheric wind and a disk wind was proposed by Pyo et al (2003) for the emission in [Fe ii] from long-slit observations at high spectral resolution (30 km s −1 ) based on the double-peaked profile with a highvelocity component at about −200 km s −1 and a low-velocity component at about −100 km s −1 , of relative strength varying along the jet. In contrast, a single disk wind where the ionization fraction varies continuously from inner to outer streamlines would predict a smooth single-peaked profile, as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

“…because of localized shocks. To better constrain the respective origins of the two velocity components noted in [Fe ii] by Pyo et al (2003), additional constraints are again needed.…”

Section: Introductionmentioning

confidence: 99%

“…5 from the star. This enables us to clarify the morphology and opening angles of the two [Fe ii] velocity components identified by Pyo et al (2003) in long-slit spectroscopy. We also identify new knots and bubble features in both the jet and counterjet, and derive the electronic density distribution along the jet, using the [Fe ii] 1.53 μm/1.64 μm ratio.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sub-arcsecond [Fe ii] spectro-imaging of the DG Tauri jet

Agra-Amboage

Dougados

Cabrit

et al. 2011

A&A

111

View full text Add to dashboard Cite

Context. The origin of protostellar jets as well as their impact on the regulation of angular momentum and the inner disk physics are still crucial open questions in star formation. Aims. We aim to test the different proposed ejection processes in T Tauri stars through high-angular resolution observations of forbidden-line emission from the inner DG Tauri microjet. Methods. We present spectro-imaging observations of the DG Tauri jet obtained with SINFONI/VLT in the lines of [Fe ii]λ1.64 μm, 1.53 μm with 0. 15 angular resolution and R = 3000 spectral resolution. We analyze the morphology and kinematics, derive electronic densities and mass-flux rates and discuss the implications for proposed jet launching models. Results. (1) We observe an onion-like velocity structure in [Fe ii] in the blueshifted jet, similar to that observed in optical lines. Highvelocity (HV) gas at -200 km s −1 is collimated inside a half-opening angle of 4 • and medium-velocity (MV) gas at -100 km s −1 in a cone with an half-opening angle 14.• (2) Two new axial jet knots are detected in the blue jet, as well as a more distant bubble with corresponding counter-bubble. The periodic knot ejection timescale is revised downward to 2.5 yrs. (3) The redshifted jet is detected only beyond 0. 7 from the star, yielding revised constraints on the disk surface density. (4) From comparison to [O i] data we infer iron depletion of a factor 3 at high velocities and a factor 10 at speeds below -100 km s −1 . (5) The mass-fluxes in each of the medium and high-velocity components of the blueshifted lobe are 1.6 ± 0.8 × 10 −8 M yr −1 , representing 0.02−0.2 of the disk accretion rate. Conclusions. The medium-velocity conical [Fe ii] flow in the DG Tau jet is too fast and too narrow to trace photo-evaporated matter from the disk atmosphere. Both its kinematics and collimation cannot be reproduced by the X-wind, nor can the "conical magnetospheric wind". The level of Fe gas phase depletion in the DG Tau medium-velocity component also rules out a stellar wind and a cocoon ejected sideways from the high-velocity beam. A quasi-steady centrifugal MHD disk wind ejected over 0.25−1.5 AU and/or episodic magnetic tower cavities launched from the disk appear as the most plausible origins for the [Fe ii] medium velocity component in the DG Tau jet. The same disk wind model can also account for the properties of the high-velocity [Fe ii] flow, although alternative origins in magnetospheric and/or stellar winds cannot be excluded for this component.

show abstract

“…However, higher spatial resolution is still required to approach the launching region of outflows close to the central star. Recently, new observational efforts such as spectro-astrometry (Takami et al 2001) and long slit spectroscopy with an adaptive optics (Pyo et al 2003(Pyo et al , 2006 have been made to reveal the circumstellar structure of TTSs down to AU scales.…”

Section: Introductionmentioning

confidence: 99%

Linear polarization in forbidden lines of the T Tauri star RY Tauri

Akitaya

Ikeda²,

Kawabata

et al. 2009

A&A

View full text Add to dashboard Cite

We performed high-dispersion spectropolarimetry for the T Tauri star RY Tauri and measured linear polarization in seven forbidden lines of [OI]λλ5577, 6300, 6364, [NII]λ6583, [SII]λλ6716, 6731, and [FeII]λ7155. This is the first high-dispersion spectropolarimetry for forbidden lines in T Tauri stars. We successfully detected intrinsic polarization in the [OI]λ6300 line. The intrinsic [OI]λ6300 polarization corrected for the foreground polarization was derived as p [OI] = 1.17 ± 0.54% and θ [OI] = 107 • ± 13 • , whereas the polarization of the nearby continuum was p cont = 2.4−3.1% and θ cont = 2 • −11 • . The position angle of [OI]λ6300 polarization is compared with the circumstellar structures found by previous studies. It is nearly perpendicular to the disk long-axis and parallel to the optical Hα jet. Both the perpendicularity and parallelism potentially suggest relatively axisymmetric distribution of the [OI]λ6300 emitting region and surrounding scattering medium. We constructed a simplified scattering model composed of a point source on a jet axis as an [OI]λ6300 emitter and a flat disk with an inner hole as a scatterer. Applying the observed polarization to the model suggests that the [OI]λ6300 emission emerges close to the central star with a possible separation of less than a few ×0.1 AU.

show abstract

Adaptive Optics Spectroscopy of the [Feii] Outflow from DG Tauri

Cited by 101 publications

References 44 publications

IR diagnostics of embedded jets: kinematics and physical characteristics of the HH46-47 jet

IR diagnostics of embedded jets: kinematics and physical characteristics of the HH46-47 jet

Sub-arcsecond [Fe ii] spectro-imaging of the DG Tauri jet

Linear polarization in forbidden lines of the T Tauri star RY Tauri

Contact Info

Product

Resources

About