The GRAVITY young stellar object survey: IV. The CO overtone emission in 51 Oph at sub-au scales
Artikel i vetenskaplig tidskrift, 2021
Context. 51 Oph is a Herbig Ae/Be star that exhibits strong near-infrared CO ro-vibrational emission at 2.3 μm, most likely originating in the innermost regions of a circumstellar disc. Aims. We aim to obtain the physical and geometrical properties of the system by spatially resolving the circumstellar environment of the inner gaseous disc. Methods. We used the second-generation Very Large Telescope Interferometer instrument 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 local thermal equilibrium ring model of the CO emission to reproduce the spectrum and CO line displacements. Results. Our interferometric data show that the star is marginally resolved at our spatial resolution, with a radius of ∼10.58 ± 2.65R·. The K-band continuum emission from the disc is inclined by 63° ± 1°, with a position angle of 116° ± 1°, 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) × 1021 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. Conclusions. 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.
Accretion, accretion disks
Stars: pre-main sequence
Stars: individual: 51 Oph
Stars: formation
Techniques: interferometric
Författare
M. Koutoulaki
Max-Planck-Gesellschaft
European Southern Observatory (ESO)
University College Dublin
Dublin Institute for Advanced Studies
R. Garcia-Lopez
University College Dublin
Max-Planck-Gesellschaft
Dublin Institute for Advanced Studies
A. Natta
Dublin Institute for Advanced Studies
Rubén Fedriani
University College Dublin
Dublin Institute for Advanced Studies
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
A. Caratti o. Garatti
Dublin Institute for Advanced Studies
Max-Planck-Gesellschaft
University College Dublin
T. P. Ray
Dublin Institute for Advanced Studies
Deirdre Coffey
Dublin Institute for Advanced Studies
Max-Planck-Gesellschaft
W. Brandner
Max-Planck-Gesellschaft
C. Dougados
Université Grenoble Alpes
P. J.V. Garcia
Instituto Superior Tecnico
Universidade do Porto
European Southern Observatory Santiago
L. Klarmann
Max-Planck-Gesellschaft
L. Labadie
Universität zu Köln
K. Perraut
Université Grenoble Alpes
J. Sanchez-Bermudez
Max-Planck-Gesellschaft
Universidad Nacional Autónoma de México
C. C. Lin
University of Hawaii
Max-Planck-Gesellschaft
A. Amorim
Instituto Superior Tecnico
Universidade de Lisboa
M. Bauböck
Max-Planck-Gesellschaft
M. Benisty
Universidad de Chile (UCH)
Université Grenoble Alpes
J. P. Berger
Université Grenoble Alpes
A. Buron
Max-Planck-Gesellschaft
P. Caselli
Max-Planck-Gesellschaft
Y. Clénet
Université de recherche Paris Sciences et Lettres
V. Coudé Du Foresto
Université de recherche Paris Sciences et Lettres
P. T. De Zeeuw
Universiteit Leiden
Max-Planck-Gesellschaft
G. Duvert
Université Grenoble Alpes
W. J. De Wit
European Southern Observatory Santiago
A. Eckart
Max-Planck-Gesellschaft
Universität zu Köln
F. Eisenhauer
Max-Planck-Gesellschaft
M. Filho
Instituto Superior Tecnico
Universidade do Porto
European Southern Observatory Santiago
F. Gao
Max-Planck-Gesellschaft
E. Gendron
Université de recherche Paris Sciences et Lettres
R. Genzel
Max-Planck-Gesellschaft
University of California
S. Gillessen
Max-Planck-Gesellschaft
R. Grellmann
Universität zu Köln
M. Habibi
Max-Planck-Gesellschaft
X. Haubois
European Southern Observatory Santiago
F. Haussmann
Max-Planck-Gesellschaft
T. Henning
Max-Planck-Gesellschaft
S. Hippler
Max-Planck-Gesellschaft
Z. Hubert
Université Grenoble Alpes
M. Horrobin
Universität zu Köln
Alejandra Jimenez-Rosales
Max-Planck-Gesellschaft
L. Jocou
Université Grenoble Alpes
P. Kervella
Université de recherche Paris Sciences et Lettres
J. Kolb
European Southern Observatory Santiago
S. Lacour
Université de recherche Paris Sciences et Lettres
J. B. Le Bouquin
Université Grenoble Alpes
P. Léna
Université de recherche Paris Sciences et Lettres
H. Linz
Max-Planck-Gesellschaft
T. Ott
Max-Planck-Gesellschaft
T. Paumard
Université de recherche Paris Sciences et Lettres
G. Perrin
Université de recherche Paris Sciences et Lettres
O. Pfuhl
European Southern Observatory (ESO)
M. C. Ramírez-Tannus
Max-Planck-Gesellschaft
C. Rau
Max-Planck-Gesellschaft
G. Rousset
Université de recherche Paris Sciences et Lettres
S. Scheithauer
Max-Planck-Gesellschaft
J. Shangguan
Max-Planck-Gesellschaft
J. Stadler
Max-Planck-Gesellschaft
O. Straub
Max-Planck-Gesellschaft
C. Straubmeier
Universität zu Köln
E. Sturm
Max-Planck-Gesellschaft
E. Van Dishoeck
Max-Planck-Gesellschaft
Universiteit Leiden
F. Vincent
Université de recherche Paris Sciences et Lettres
S. von Fellenberg
Max-Planck-Gesellschaft
F. Widmann
Max-Planck-Gesellschaft
E. Wieprecht
Max-Planck-Gesellschaft
M. Wiest
Universität zu Köln
E. Wiezorrek
Max-Planck-Gesellschaft
S. Yazici
Max-Planck-Gesellschaft
Universität zu Köln
G. Zins
European Southern Observatory Santiago
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 645 A50Ämneskategorier
Astronomi, astrofysik och kosmologi
Atom- och molekylfysik och optik
Geofysik
DOI
10.1051/0004-6361/202038000