1. The GRAVITY young stellar object survey: IV. The CO overtone emission in 51 Oph at sub-au scales
- Author
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GRAVITY, Collaboration, Koutoulaki, M., Lopez, R. Garcia, Natta, A., Fedriani, R., oGaratti, A. Caratti, Ray, T. P., Coffey, D., Brandner, W., Dougados, C., Garcia, P. J. V, Klarmann, L., Labadie, L., Perraut, K., Sanchez-Bermudez, J., Lin, C. -C., Amorim, A., Bauböck, M., Benisty, M., Berger, J. P., Buron, A., Caselli, P., Clénet, Y., Foresto, V. Coudé Du, De Zeeuw, P. T., Duvert, G., de Wit, W., Eckart, A., Eisenhauer, F., Filho, M., Gao, F., Gendron, E., Genzel, R., Gillessen, S., Grellmann, R., Habibi, M., Haubois, X., Haussmann, F., Henning, T., Hippler, S., Hubert, Z., Horrobin, M., Rosales, A. Jimenez, Jocou, L., Kervella, P., Kolb, J., Lacour, S., Bouquin, J. -B. Le, Léna, P., Linz, H., Ott, T., Paumard, T., Perrin, G., Pfuhl, O., Ramírez-Tannus, M. C., Rau, C., Rousset, G., Scheithauer, S., Shangguan, J., Stadler, J., Straub, O., Straubmeier, C., Sturm, E., Van Dishoeck, E., Vincent, F., Von fellenberg, S., Widmann, F., Wieprecht, E., Wiest, M., Wiezorrek, E., Yazici, S., Zins, G., Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Dublin Institute for Advanced Studies (DIAS), School of Physics [UCD Dublin], University College Dublin [Dublin] (UCD), European Southern Observatory (ESO), Chalmers University of Technology [Gothenburg, Sweden], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Faculdade de Engenharia da Universidade do Porto (FEUP), Universidade do Porto, Centro de Astrofísica e Gravitação (CENTRA), European Southern Observatory [Santiago] (ESO), I. Physikalisches Institut [Köln], Universität zu Köln, Instituto de Astronomía, Univ. Nacional Autónoma de México, Universidad Nacional Autónoma de México (UNAM), Institute for Astronomy, University of Hawai'i at Manoa, Universidade de Lisboa (ULISBOA), Max Planck Institute for Extraterrestrial Physics (MPE), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Sterrewacht Leiden, Universiteit Leiden [Leiden], Max-Planck-Institut für Radioastronomie (MPIFR), Department of Physics [Berkeley], University of California [Berkeley], and University of California-University of California
- Subjects
Accretion ,Be star ,Techniques: Interferometric ,Astrophysics::High Energy Astrophysical Phenomena ,Overtone ,Young stellar object ,FOS: Physical sciences ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,01 natural sciences ,Accretion Disks ,0103 physical sciences ,Stars: Pre-Main Sequence ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Image resolution ,Solar and Stellar Astrophysics (astro-ph.SR) ,Astrophysics::Galaxy Astrophysics ,Physics ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,010308 nuclear & particles physics ,Astronomy and Astrophysics ,Stars: Individual: 51 Oph ,Position angle ,Astrophysics - Astrophysics of Galaxies ,Interferometry ,Wavelength ,Stars ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Earth and Planetary Astrophysics ,Stars: Formation - Abstract
51 Oph is a Herbig Ae/Be star that exhibits strong near-infrared CO ro-vibrational emission at 2.3 micron, most likely originating in the innermost regions of a circumstellar disc. We aim to obtain the physical and geometrical properties of the system by spatially resolving the circumstellar environment of the inner gaseous disc. We used the second-generation VLTI/GRAVITY to spatially resolve the continuum and the CO overtone emission. We obtained data over 12 baselines with the auxiliary telescopes and derive visibilities, and the differential and closure phases as a function of wavelength. We used a simple LTE ring model of the CO emission to reproduce the spectrum and CO line displacements. Our interferometric data show that the star is marginally resolved at our spatial resolution, with a radius of 10.58+-2.65 Rsun.The K-band continuum emission from the disc is inclined by 63+-1 deg, with a position angle of 116+-1 deg, and 4+-0.8 mas (0.5+-0.1 au) across. The visibilities increase within the CO line emission, indicating that the CO is emitted within the dust-sublimation radius.By modelling the CO bandhead spectrum, we derive that the CO is emitted from a hot (T=1900-2800 K) and dense (NCO=(0.9-9)x10^21 cm^-2) gas. The analysis of the CO line displacement with respect to the continuum allows us to infer that the CO is emitted from a region 0.10+-0.02 au across, well within the dust-sublimation radius. The inclination and position angle of the CO line emitting region is consistent with that of the dusty disc. Our spatially resolved interferometric observations confirm the CO ro-vibrational emission within the dust-free region of the inner disc. Conventional disc models exclude the presence of CO in the dust-depleted regions of Herbig AeBe stars. Ad hoc models of the innermost disc regions, that can compute the properties of the dust-free inner disc, are therefore required., Accepted in A&A
- Published
- 2021