The GRAVITY young stellar object survey -- XI. Probing the inner disk and magnetospheric accretion region of CI Tau

Abstract

Aims: We aim at spatially and spectrally resolving the innermost scale of the young stellar object CI Tau to constrain the inner disk properties and better understand the magnetospheric accretion phenomenon. Methods: The high sensitivity offered by the combination of the four 8-m telescopes of the VLTI allied with the spectral resolution of the K-band beam combiner GRAVITY offers a unique capability to probe the sub-au scale of the CI Tau system, tracing both dust and gas emission regions. We develop a geometrical model to fit the interferometric observables and constrain the physical properties of the inner dusty disk. The continuum-corrected pure line visibilities have been used to estimate the size of the Br$\gamma$ emitting region. Results: From the K-band continuum study, we report an highly inclined resolved inner dusty disk, with an inner edge located at a distance of $21\pm 2R_{\star }$ from the central star, which is significantly larger than the dust sublimation radius (R${}_{sub}=4.3$ to $8.6R_{\star }$). The inner disk appears misaligned compared to the outer disk observed by ALMA and the non-zero closure phase indicates the presence of a bright asymmetry on the south-west side. From the differential visibilities across the Br$\gamma$ line, we resolve the line emitting region, and measure a size of $4.8_{-1.0}^{+0.8}$ $R_{\star }$. Conclusions: The extended inner disk edge compared to the dust sublimation radius is consistent with the claim of an inner planet, CI Tau b, orbiting close-in. The inner-outer disk misalignment may be induced by gravitational torques or magnetic warping. The size of the Br$\gamma$ emitting region is consistent with the magnetospheric accretion process. Assuming it corresponds to the magnetospheric radius, it is significantly smaller than the co-rotation radius, which suggests an unstable accretion regime that is consistent with CI Tau being a burster.

arXiv comment12 pages, 13 figures

References in corpus (47)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• emcee: The MCMC Hammer
• Gaia Data Release 3: Summary of the content and survey properties
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The K2 Mission: Characterization and Early results
• Magnetic fields of non-degenerate stars
• First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
• X-Shooter spectroscopy of young stellar objects in Lupus: Accretion properties of class II and transitional objects
• The inner regions of protoplanetary disks
• On the Interferometric Sizes of Young Stellar Objects
• Accretion funnels onto weakly magnetized young stars
• Unstable Disk Accretion to Magnetized Stars: First Global 3D MHD Simulations
• 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
• Near-Infrared interferometry of Eta Carinae with high spatial and spectral resolution using the VLTI and the AMBER instrument
• A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau
• Pseudomagnitudes and Differential Surface Brightness: Application to the apparent diameter of stars
• Masses and Implications for Ages of Low-Mass Pre-Main Sequence Stars in Taurus and Ophiuchus
• High resolution millimetre imaging of the CI Tau protoplanetary disc - a massive ensemble of protoplanets from 0.1 - 100 au
• Boundary between Stable and Unstable Regimes of Accretion. Ordered and Chaotic Unstable Regimes
• Interaction between massive planets on inclined orbits and circumstellar discs
• Accretion, Outflows, and Winds of Magnetized Stars
• The masses of young stars: CN as a probe of dynamical masses
• Misaligned disks induced by infall
• The inner radius of T Tauri disks estimated from near-infrared interferometry: the importance of scattered light
• PENELLOPE: the ESO data legacy program to complement the Hubble UV Legacy Library of Young Stars (ULLYSES) I. Survey presentation and accretion properties of Orion OB1 and $\sigma$-Orionis
• The GRAVITY fringe tracker
• The VLTI / PIONIER near-infrared interferometric survey of southern T Tauri stars. I. First results
• Warping a protoplanetary disc with a planet on an inclined orbit
• The magnetic field and accretion regime of CI Tau
• Connecting the shadows: probing inner disk geometries using shadows in transitional disks
• 3D MHD Simulations of Accretion onto Stars with Tilted Magnetic and Rotational Axes
• Magnetic torques on T Tauri stars: accreting vs. non-accreting systems
• A measure of the size of the magnetospheric accretion region in TW Hydrae
• The GRAVITY Young Stellar Object survey. VII. The inner dusty disks of T Tauri stars
• The Many-Faceted Light Curves of Young Disk-bearing Stars in Taurus as Seen by K2
• The ODYSSEUS Survey. Motivation and First Results: Accretion, Ejection, and Disk Irradiation of CVSO 109
• Probing the magnetospheric accretion region of the young pre-transitional disk system DoAr 44 using VLTI/GRAVITY
• CO Detected in CI Tau b: Hot Start Implied by Planet Mass and M${}_K$
• GIARPS High-resolution Observations of T Tauri stars (GHOsT). III. A pilot study of stellar and accretion properties
• Three-Dimensional Disk-Satellite Interaction: Torques, Migration, and Observational Signatures
• Investigating the magnetospheric accretion process in the young pre-transitional disk system DoAr 44 (V2062~Oph). A multiwavelength interferometric, spectropolarimetric, and photometric observing campaign
• New insights on the near-infrared veiling of young stars using CFHT/SPIRou data
• The dipper population of Taurus seen with K2
• NGC 1068: No change in the mid-IR torus structure despite X-ray variability
• Spectroscopic and interferometric signatures of magnetospheric accretion in young stars

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• Long period modulation of the classical T Tauri star CI Tau: evidence for an eccentric close-in massive planet at 0.17 au
• Ro-vibrational Spectroscopy of CI Tau -- Evidence of a Multi-Component Eccentric Disk Induced by a Planet
• Multi-frequency analysis of the ALMA and VLA high resolution continuum observations of the substructured disc around CI Tau. Preference for sub-mm-sized low-porosity amorphous carbon grains
• The High-resolution Accretion Disks of Embedded protoStars (HADES) simulations. I. Impact of Protostellar Magnetic Fields on the Accretion Modes
• The GRAVITY young stellar object survey XIV : Investigating the magnetospheric accretion-ejection processes in S CrA N
• Gas chemistry in the dust depleted inner regions of protoplanetary disks. I. Near-IR spectra and overtones