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标题：The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-au resolution
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作者：R. Garcia Lopez ; K. Perraut ; A. Caratti o Garatti 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2017
卷号：608
页码：1-12
DOI：10.1051/0004-6361/201731058
语种：English
出版社：EDP Sciences
摘要：Aims.To investigate the inner regions of protoplanetary discs, we performed near-infrared interferometric observations of the classical T Tauri binary system S CrA.Methods.We present the first VLTI-GRAVITY high spectral resolution (R~ 4000) observations of a classical T Tauri binary, S CrA (composed of S CrA N and S CrA S and separated by~1.̋4), combining the four 8m telescopes in dual-field mode.Results.Our observations in the near-infraredK-band continuum reveal a disc around each binary component, with similar half-flux radii of about 0.1 au atd~ 130 pc, inclinations (i= 28 ± 3°andi= 22 ± 6°), and position angles (PA = 0°±6°and PA = –2°±12°), suggesting that they formed from the fragmentation of a common disc. The S CrA N spectrum shows bright He iand Brγline emission exhibiting inverse P Cygni profiles, typically associated with infalling gas. The continuum-compensated Brγline visibilities of S CrA N show the presence of a compact Brγemitting region whose radius is about~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 Brγline components is marginally detected.Conclusions.The presence of an inverse P Cygni profile in the He iand Brγlines, along with the tentative detection of a slightly larger size of the blue-shifted Brγline component, hint at the simultaneous presence of a wind and magnetospheric accretion in S CrA N.
关键词：enstars: formationcircumstellar matterISM: jets and outflowsISM: individual objects: S CrAinfrared: ISMtechniques: interferometric