The GRAVITY young stellar object survey XII. The hot gas disk component in Herbig Ae/Be stars
Journal article, 2024
Context. The region of protoplanetary disks closest to a star (within 1–2 au) is shaped by a number of different processes, from accretion of the disk material onto the central star to ejection in the form of winds and jets. Optical and near-IR emission lines are potentially good tracers of inner disk processes if very high spatial and/or spectral resolution are achieved. Aims. In this paper, we exploit the capabilities of the VLTI-GRAVITY near-IR interferometer to determine the location and kinematics of the hydrogen emission line Brγ. Methods. We present VLTI-GRAVITY observations of the Brγ line for a sample of 26 stars of intermediate mass (HAEBE), the largest sample so far analysed with near-IR interferometry. Results. The Brγ line was detected in 17 objects. The emission is very compact (in most cases only marginally resolved), with a size of 10–30 R∗(1–5 mas). About half of the total flux comes from even smaller regions, which are unresolved in our data. For eight objects, it was possible to determine the position angle (PA) of the line-emitting region, which is generally in agreement with that of the inner-dusty disk emitting the K-band continuum. The position-velocity pattern of the Brγ line-emitting region of the sampled objects is roughly consistent with Keplerian rotation. The exception is HD 45677, which shows more extended emission and more complex kinematics. The most likely scenario for the Brγ origin is that the emission comes from an MHD wind launched very close to the central star, in a region well within the dust sublimation radius. An origin in the bound gas layer at the disk surface cannot be ruled out, while accreting matter provides only a minor fraction of the total flux. Conclusions. These results show the potential of near-IR spectro-interferometry to study line emission in young stellar objects.
circumstellar matter
stars: formation
techniques: interferometric
stars: variables: T Tauri, Herbig Ae/Be
Author
R. Garcia-Lopez
Max Planck Society
University College Dublin
A. Natta
Dublin Institute for Advanced Studies
Rubén Fedriani
Institute of Astrophysics of Andalusia (IAA)
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A. Caratti o. Garatti
Osservatorio Astronomico di Capodimonte
Max Planck Society
J. Sanchez-Bermudez
Universidad Nacional Autónoma de México
Max Planck Society
K. Perraut
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
C. Dougados
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
Y. I. Bouarour
University College Dublin
J. Bouvier
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
W. Brandner
Max Planck Society
P. Garcia
Instituto Superior Tecnico
University of Porto
M. Koutoulaki
University of Leeds
L. Labadie
University of Cologne
H. Linz
Max Planck Society
E. Alécian
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
M. Benisty
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
J. P. Berger
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
G. Bourdarot
Max Planck Society
P. Caselli
Max Planck Society
Y. Clénet
Paris Observatory
P. T. De Zeeuw
Leiden University
R. I. Davies
Max Planck Society
A. Eckart
Max Planck Society
University of Cologne
F. Eisenhauer
Max Planck Society
N. M. Förster-Schreiber
Max Planck Society
E. Gendron
Paris Observatory
S. Gillessen
Max Planck Society
Sierra L. Grant
Max Planck Society
T. Henning
Max Planck Society
P. Kervella
Paris Observatory
S. Lacour
Paris Observatory
V. Lapeyrère
Paris Observatory
J. B. Le Bouquin
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
D. Lutz
Max Planck Society
F. Mang
Max Planck Society
H. Nowacki
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
T. Ott
Max Planck Society
T. Paumard
Paris Observatory
G. Perrin
Paris Observatory
J. Shangguan
Max Planck Society
T. Shimizu
Max Planck Society
A. Soulain
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
C. Straubmeier
University of Cologne
E. Sturm
Max Planck Society
L. J. Tacconi
Max Planck Society
E. F. van Dishoeck
Leiden University
F. Vincent
Paris Observatory
F. Widmann
Max Planck Society
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 684 A43Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/202245804