The asymmetric inner disk of the Herbig Ae star HD 163296 in the eyes of VLTI/MATISSE: evidence for a vortex?

Abstract

Context. The inner few au region of planet-forming disks is a complex environment. High angular resolution observations have a key role in understanding the disk structure and the dynamical processes at work. Aims. In this study we aim to characterize the mid-infrared brightness distribution of the inner disk of the young intermediate-mass star HD 163296, from VLTI/MATISSE observations. Methods. We use geometric models to fit the data. Our models include a smoothed ring, a flat disk with inner cavity, and a 2D Gaussian. The models can account for disk inclination and for azimuthal asymmetries as well. We also perform numerical hydro-dynamical simulations of the inner edge of the disk. Results. Our modeling reveals a significant brightness asymmetry in the L-band disk emission. The brightness maximum of the asymmetry is located at the NW part of the disk image, nearly at the position angle of the semimajor axis. The surface brightness ratio in the azimuthal variation is $3.5\pm 0.2$. Comparing our result on the location of the asymmetry with other interferometric measurements, we confirm that the morphology of the $r<0.3$ au disk region is time-variable. We propose that this asymmetric structure, located in or near the inner rim of the dusty disk, orbits the star. For the physical origin of the asymmetry, we tested a hypothesis where a vortex is created by Rossby wave instability, and we find that a unique large scale vortex may be compatible with our data. The half-light radius of the L-band emitting region is $0.33\pm 0.01$ au, the inclination is ${52^{\circ }}_{-7^{\circ }}^{+5^{\circ }}$, and the position angle is $143^{\circ }\pm 3^{\circ }$. Our models predict that a non-negligible fraction of the L-band disk emission originates inside the dust sublimation radius for $\mu$m-sized grains. Refractory grains or large ($\gtrsim 10\mu$m-sized) grains could be the origin for this emission.

accepted for publication in A&A

References in corpus (22)

• Gaps, Rings, and Non-Axisymmetric Structures in Protoplanetary Disks - From Simulations to ALMA Observations
• Radiative transfer in very optically thick circumstellar disks
• Three radial gaps in the disk of TW Hydrae imaged with SPHERE
• Meridional flows in the disk around a young star
• Structure of Herbig AeBe disks at the milliarcsecond scale A statistical survey in the H band using PIONIER-VLTI
• A Tale of Two Herbig Ae stars -MWC275 and AB Aurigae: Comprehensive Models for SED and Interferometry
• 3D Radiation Non-ideal Magnetohydrodynamical Simulations Of The Inner Rim In Protoplanetary Disks
• PAH chemistry and IR emission from circumstellar disks
• Variability of Disk Emission in Pre-Main Sequence and Related Stars. I. HD 31648 and HD 163296 - Isolated Herbig Ae Stars Driving Herbig-Haro Flows
• Near-Infrared Interferometric, Spectroscopic, and Photometric Monitoring of T Tauri Inner Disks
• Mid-infrared size survey of Young Stellar Objects: Description of Keck segment-tilting experiment and basic results
• The GRAVITY Young Stellar Object survey -- I. Probing the disks of Herbig Ae/Be stars in terrestrial orbits
• Spectrally Dispersed K-Band Interferometric Observations of Herbig Ae/Be Sources: Inner Disk Temperature Profiles
• A catalogue of stellar diameters and fluxes for mid-infrared interferometry
• Observability of Forming Planets and their Circumplanetary Disks II. -- SEDs and Near-Infrared Fluxes
• A family portrait of disk inner rims around Herbig Ae/Be stars: Hunting for warps, rings, self shadowing, and misalignments in the inner astronomical units
• Gas and dust in the inner disk of the Herbig Ae star MWC 758
• Disk Illumination and Jet Variability of the Herbig Ae Star HD 163296 Using Multi-Epoch HST/STIS Optical, Near-IR, and Radio Imagery and Spectroscopy
• Dynamical signatures of Rossby vortices in cavity-hosting disks
• Why Chromatic Imaging Matters
• MATISSE: specifications and expected performances
• On the inner disk structure of MWC480: evidence for asymmetries?

Cited by in corpus (25)

• Molecules with ALMA at Planet-forming Scales (MAPS) I: Program Overview and Highlights
• Dust growth and evolution in protoplanetary disks
• Herbig Stars: A Quarter Century of Progress
• The impact of dynamic pressure bumps on the observational properties of protoplanetary disks
• The GRAVITY Young Stellar Object Survey. VI. Mapping the variable inner disk of HD 163296 at sub-au scales
• Millimeter Gap Contrast as a Probe for Turbulence Level in Protoplanetary Disks
• The disk of FU Orionis viewed with MATISSE/VLTI: first interferometric observations in $L$ and $M$ bands
• The Polstar High Resolution Spectropolarimetry MIDEX Mission
• Spatial distribution of crystalline silicates in protoplanetary disks: How to interpret mid-infrared observations
• Potential and sky coverage for off-axis fringe tracking in optical long baseline interferometry
• Mid-infrared evidence for iron-rich dust in the multi-ringed inner disk of HD 144432
• Global magnetohydrodynamic simulations of the inner regions of protoplanetary discs. I. Zero-net flux regime
• Primordial dust rings, hidden dust mass, and the first generation of planetesimals in gravitationally unstable protoplanetary disks
• Spatially resolving polycyclic aromatic hydrocarbons in Herbig Ae disks with VISIR-NEAR at the VLT
• Self-gravity in thin-disc simulations of protoplanetary discs: smoothing length rectified and generalised to bi-fluids
• UV Spectropolarimetry with Polstar: Protoplanetary Disks
• Multi dust species inner rim in magnetized protoplanetary disks
• Morphology and dynamical stability of self-gravitating vortices: Numerical simulations
• The Dynamic Inner Disk of a Planet Forming Star
• Planetary nurseries: vortices formed at smooth viscosity transition
• A gap at 1 au in the disk of DI Cha A revealed by infrared interferometry
• The asymmetric structure of the inner disc around HD 142527 A with VLTI/MATISSE
• Probing inner and outer disk misalignments in transition disks
• The complex inner disk of the Herbig Ae star HD 100453 with VLTI/MATISSE
• The MATISSE view of the inner region of the RY Tau protoplanetary disk