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

• Published in: arXiv.org
• Main Authors: R Garcia Lopez, Perraut, K, A Caratti o Garatti, Lazareff, B, Sanchez-Bermudez, J, Benisty, M, Dougados, C, Labadie, L, Brandner, W, Garcia, P J V, Henning, Th, Ray, T P, Abuter, R, Amorim, A, Anugu, N, Berger, J P, Bonnet, H, Buron, A, Caselli, P, Clénet, Y, V Coudé du Foresto, de Wit, W, Deen, C, Delplancke-Ströbele, F, Dexter, J, Eckart, A, Eisenhauer, F, Garcia Dabo, C E, Gendron, E, Genzel, R, Gillessen, S, Haubois, X, Haug, M, Haussmann, F, Hippler, S, Hubert, Z, Hummel, C A, Horrobin, M, Jocou, L, Kellner, S, Kervella, P, Kulas, M, Kolb, J, Lacour, S, J -B Le Bouquin, Léna, P, Lippa, M, Mérand, A, Müller, E, Ott, T, Panduro, J, Paumard, T, Perrin, G, Pfuhl, O, Ramirez, A, Rau, C, R -R Rohloff, Rousset, G, Scheithauer, S, Schöller, M, Straubmeier, C, Sturm, E, Thi, W F, E van Dishoeck, Vincent, F, Waisberg, I, Wank, I, Wieprecht, E, Wiest, M, Wiezorrek, E, Woillez, J, Yazici, S, Zins, G, GRAVITY Collaboration
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 05.09.2017
• Subjects: Accretion disks; Deposition; Magnetospheres; Physics - Solar and Stellar Astrophysics; Planet formation; Protoplanets; Spectral resolution; Stellar winds; T Tauri stars; Telescopes
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1709.01348

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.