An asymmetry detected in the disk of κ Canis Majoris with AMBER/VLTI
Domiciano de Souza, A
Le Coarer, E
Hernandez Utrera, O
Le Contel, D
Le Contel, J-M
von der Lühe, O
Astronomy and Astrophysics
Aims. We study the geometry and kinematics of the circumstellar environment of the Be star κ CMa in the Brγ emission line and its nearby continuum. Methods. We use the VLTI/AMBER instrument operating in the K band which provides a spatial resolution of about 6 mas with a spectral resolution of 1500 to study the kinematics within the disk and to infer its rotation law. In order to obtain more kinematical constraints we also use an high spectral resolution Paβ line profile obtain in December 2005 at the Observatorio do Pico do Dios, Brazil and we compile V/R line profile variations and spectral energy distribution data points from the literature. Results. Using differential visibilities and differential phases across the Brγ line we detect an asymmetry in the disk. Moreover, we found that κ CMa seems difficult to fit within the classical scenario for Be stars, illustrated recently by α Arae observations, i.e. a fast rotating B star close to its breakup velocity surrounded by a Keplerian circumstellar disk with an enhanced polar wind. Finally we discuss the possibility for κ CMa to be a critical rotator with a Keplerian rotating disk and try to see if the detected asymmetry can be interpreted within the ”one-armed” viscous disk framework.
The AMBER project has benefited from funding from the French Centre National de la Recherche Scientifique (CNRS) through the Institut National des Sciences de l’Univers (INSU) and its Programmes Nationaux (ASHRA, PNPS). The authors from the French laboratories would like to thank the successive directors of the INSU/CNRS directors. The authors from the the Arcetri Observatory acknowledge partial support from MIUR grants and from INAF grants. C. Gil work was supported in part by the Fundac¸˜ao para a Ciˆencia e a Tecnologia through project POCTI/CTE-AST/55691/2004 from POCTI, with funds from the European program FEDER
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.
Variant title for accepted version: An asymmetry detected in the disk of κ CMa⋆ with the VLTI/AMBER
Vol. 464, pp. 73-79