Details

Autor(en) / Beteiligte

• Varga, J
• Hogerheijde, M
• Boekel, R van
• Klarmann, L
• Petrov, R
• Waters, L B F M
• Lagarde, S
• Berio, Ph
• Weigelt, G
• Robbe-Dubois, S
• Lopez, B
• Millour, F
• Augereau, J-C
• Meheut, H
• Meilland, A
• Henning, Th
• Jaffe, W
• Bettonvil, F
• Bristow, P
• Hofmann, K-H
• Matter, A
• Allouche, F
• Donnan, F
• Heininger, M
• Cruzalebes, P
• Glindermann, A
• Meisenheimer, K
• Paladini, C
• Scholler, M
• Woillez, J
• Venema, L
• Kokoulina, E
• Yoffe, G
• Abadie, S
• Abuter, R
• Accardo, M
• Adler, T
• Antonelli, P
• Bohm, A
• Bailet, C
• Bazin, G
• Beltran, J
• Boland, W
• Bourget, P
• Brast, R
• Bresson, Y
• Chelli, A
• Cid, C
• Clausse, J-M
• Conzelmann, R D
• Danchi, W-C
• Hann, M De
• Delbo, M
• Ebert, M
• Fantei, Y
• Gallenne, A
• Garces, E
• Herrera, J C Gonzalez
• Guitton, F
• Hron, J
• Hubin, N
• Huerta, R
• Ives, D
• Jakob, G
• Jasko, A
• Jochum, L
• Kragt, J
• Kroes, G
• Kuindersma, S
• Laun, W
• Leinert, C
• Lizon, J-L
• Lopez, M
• Merand, A
• Mauclert, N
• Maurer, T
• Meisner, J
• Meixner, K
• Mohr, L
• Morel, S
• Mosoni, L
• Navarro, R
• Pallanca, L
• Pasquini, L
• Percheron, I
• Ridinger, A
• Rigal, F
• Riquelme, M
• Rivinius, Th
• Roelfsema, R
• Schuhler, N
• Schuil, M
• Stee, P
• Stephan, C
• Horst, R ter
• Tromp, N
• Vakili, F
• Duin, A van
• Wittkowski, M
• Wrhel, F

Titel

The Asymmetric Inner Disk of the Herbig Ae Star HD 163296 in the Eyes of VLTI/MATISSE: Evidence for a Vortex?

Ist Teil von

• Astronomy and astrophysics (Berlin), 2021-03, Vol.647, p.A56

Ort / Verlag

Goddard Space Flight Center: EDP Sciences

Erscheinungsjahr

2021

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• 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.