1. The Asymmetric Inner Disk of the Herbig Ae Star HD 163296 in the Eyes of VLTI/MATISSE: Evidence for a Vortex?
- Author
-
J Varga, M Hogerheijde, R van Boekel, L Klarmann, R Petrov, L B F M Waters, S Lagarde, E Pantin, Ph Berio, G Weigelt, S Robbe-Dubois, B Lopez, F Millour, J-C Augereau, H Meheut, A Meilland, Th Henning, W Jaffe, F Bettonvil, P Bristow, K-H Hofmann, A Matter, G Zins, S Wolf, F Allouche, F Donnan, D Schertl, C Dominik, M Heininger, M Lehmitz, P Cruzalebes, A Glindermann, K Meisenheimer, C Paladini, M Scholler, J Woillez, L Venema, E Kokoulina, G Yoffe, P Abraham, S Abadie, R Abuter, M Accardo, T Adler, T Agocs, P Antonelli, A Bohm, C Bailet, G Bazin, U Beckmann, J Beltran, W Boland, P Bourget, R Brast, Y Bresson, L Burtscher, R Castillo, A Chelli, C Cid, J-M Clausse, C Connot, R D Conzelmann, W-C Danchi, M De Hann, M Delbo, M Ebert, E Elswijk, Y Fantei, R Frahm, V Gamez Rosas, A Gabasch, A Gallenne, E Garces, P Girard, F Y J Gonte, J C Gonzalez Herrera, U Graser, P Guajardo, F Guitton, X Haubois, J Hron, N Hubin, R Huerta, J W Isbell, D Ives, G Jakob, A Jasko, L Jochum, R Klein, J Kragt, G Kroes, S Kuindersma, L Labadie, W Laun, R Le Poole, C Leinert, J-L Lizon, M Lopez, A Merand, A Marcotto, N Mauclert, T Maurer, L H Mehrgan, J Meisner, K Meixner, M Mellein, L Mohr, S Morel, L Mosoni, R Navarro, U Neumann, E NuBbaum, L Pallanca, L Pasquini, I Percheron, J-U Pott, E Ponza, A Ridinger, F Rigal, M Riquelme, Th Rivinius, R Roelfsema, R-R Rohloff, S Rousseau, N Schuhler, M Schuil, A Soulain, P Stee, C Stephan, R ter Horst, N Tromp, F Vakili, A van Duin, J Vinther, M Wittkowski, and F Wrhel
- Subjects
Astronomy - Abstract
Context.A complex environment exists in the inner few astronomical units of planet-forming disks. High-angular-resolution observa-tions play a key role in our understanding of 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-massstar HD 163296 from early VLTI/MATISSE observations taken in theL- andN-bands. We put special emphasis on the detection ofpotential disk asymmetries.Methods.We use simple geometric models to fit the interferometric visibilities and closure phases. Our models include a smoothedring, a flat disk with an inner cavity, and a 2D Gaussian. The models can account for disk inclination and for azimuthal asymmetriesas well. We also perform numerical hydrodynamical simulations of the inner edge of the disk.Results.Our modeling reveals a significant brightness asymmetry in theL-band disk emission. The brightness maximum of the asym-metry is located at the NW part of the disk image, nearly at the position angle of the semimajor axis. The surface brightness ratio inthe azimuthal variation is3.5±0.2. Comparing our result on the location of the asymmetry with other interferometric measurements,we confirm that the morphology of ther<0.3au disk region is time-variable. We propose that this asymmetric structure, located in ornear the inner rim of the dusty disk, orbits the star. To find the physical origin of the asymmetry, we tested a hypothesis where a vortexis created by Rossby wave instability, and we find that a unique large-scale vortex may be compatible with our data. The half-lightradius of theL-band-emitting region is0.33±0.01au, the inclination is52◦+5◦−7◦, and the position angle is143◦±3◦. Our models predictthat a non-negligible fraction of theL-band disk emission originates inside the dust sublimation radius forμm-sized grains. Refractorygrains or large (&10μm-sized) grains could be the origin of this emission.N-band observations may also support a lack of smallsilicate grains in the innermost disk (r.0.6au), in agreement with our findings fromL-band data.
- Published
- 2021
- Full Text
- View/download PDF