The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-au resolution

Abstract

To investigate the inner regions of protoplanetary disks, we performed near-infrared interferometric observations of the classical TTauri binary system S CrA. We present the first VLTI-GRAVITY high spectral resolution ($R\sim$4000) observations of a classical TTauri binary, S CrA (composed of S CrA N and S CrA S and separated by $\sim$1.4"), combining the four 8-m telescopes in dual-field mode. Our observations in the near-infrared K-band continuum reveal a disk around each binary component, with similar half-flux radii of about 0.1 au at d$\sim$130 pc, inclinations ($i=$28$\pm$3${}^o$\ and $i=$22$\pm$6${}^o$), and position angles (PA=0${}^o\pm$6${}^o$ and PA=-2${}^o\pm$12${}^o$), suggesting that they formed from the fragmentation of a common disk. The S CrA N spectrum shows bright HeI and Br$\gamma$ line emission exhibiting inverse P-Cygni profiles, typically associated with infalling gas. The continuum-compensated Br$\gamma$ line visibilities of S CrA N show the presence of a compact Br$\gamma$ emitting region the radius of which is about $\sim$0.06 au, which is twice as big as the truncation radius. This component is mostly tracing a wind. Moreover, a slight radius change between the blue- and red-shifted Br$\gamma$ line components is marginally detected. The presence of an inverse P-Cygni profile in the HeI and Br$\gamma$ lines, along with the tentative detection of a slightly larger size of the blue-shifted Br$\gamma$ line component, hint at the simultaneous presence of a wind and magnetospheric accretion in S CrA N.

arXiv commentAccepted by A&A

References in corpus (36)

• Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
• First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
• Interferometric data reduction with AMBER/VLTI.Principle,estimators and illustration
• Probing T Tauri Accretion and Outflow with 1 Micron Spectroscopy
• A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable Disk
• The structure and dynamics of molecular gas in planet-forming zones: A CRIRES spectro-astrometric survey
• The formation of close binary systems
• Astrophysics of Young Star Binaries
• Structure of Herbig AeBe disks at the milliarcsecond scale A statistical survey in the H band using PIONIER-VLTI
• The origin of hydrogen line emission for five Herbig Ae/Be stars spatially resolved by VLTI/AMBER spectro-interferometry
• A Tale of Two Herbig Ae stars -MWC275 and AB Aurigae: Comprehensive Models for SED and Interferometry
• Misaligned Protoplanetary Disks in a Young Binary System
• Multidimensional models of hydrogen and helium emission line profiles for classical T Tauri Stars: method, tests and examples
• Near-Infrared interferometry of Eta Carinae with high spatial and spectral resolution using the VLTI and the AMBER instrument
• Spectral variability of classical T Tauri stars accreting in an unstable regime
• The Spitzer Survey of Interstellar Clouds in the Gould Belt. III. A Multi-Wavelength View of Corona Australis
• Strong near-infrared emission in the sub-AU disk of the Herbig Ae star HD163296: evidence for refractory dust?
• Relating jet structure to photometric variability: the Herbig Ae star HD 163296
• A Turbulent Interstellar Medium Origin of the Binary Period Distribution
• VLTI/AMBER spectro-interferometry of the Herbig Be star MWC 297 with spectral resolution 12 000
• The VLTI / PIONIER near-infrared interferometric survey of southern T Tauri stars. I. First results
• Spectrally Dispersed K-Band Interferometric Observations of Herbig Ae/Be Sources: Inner Disk Temperature Profiles
• Spatially and Spectrally Resolved Hydrogen Gas within 0.1 AU of T Tauri and Herbig Ae/Be Stars
• Constraining the Sub-AU-Scale Distribution of Hydrogen and Carbon Monoxide Gas around Young Stars with the Keck Interferometer
• Resolving the gap and AU-scale asymmetries in the pre-transitional disk of V1247 Orionis
• Protostars, multiplicity, and disk evolution in the Corona Australis region: A Herschel Gould Belt Study
• Origin of the wide-angle hot H2 in DG Tauri: New insight from SINFONI spectro-imaging
• AMBER/VLTI high spectral resolution observations of the Br$\gamma$ emitting region in HD 98922. A compact disc wind launched from the inner disc region
• Probing the accretion-ejection connection with VLTI/AMBER: High spectral resolution observations of the Herbig Ae star HD163296
• High-resolution Br-gamma spectro-interferometry of the transitional Herbig Ae/Be star HD 100546: a Keplerian gaseous disc inside the inner rim
• Probing the wind launching regions of the Herbig Be star HD 58647 with high spectral resolution interferometry
• Optical spectroscopy of close companions to nearby Herbig Ae/Be and T Tauri stars
• Investigating the origin and spectroscopic variability of the near-infrared HI lines in the Herbig star VV Ser
• H2 flows in the Corona Australis cloud and their driving sources
• Doppler Probe of Accretion onto a T Tauri star
• Revealing the inner circumstellar disk of the T Tauri star S CrA N using the VLTI

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