ALMA observations of TiO2 around VY CMa
Paper in proceeding, 2016
Titanium dioxide, TiO2, is a refractory species that could play a crucial role in the dust-condensation sequence around oxygen-rich evolved stars. We present and discuss the detections of 15 emission lines of TiO2 with ALMA in the complex environment of the red supergiant VY CMa. The observations reveal a highly clumpy, anisotropic outflow in which the TiO2 emission likely traces gas exposed to the stellar radiation field. We find evidence for a roughly east-west oriented, accelerating bipolar-like structure, of which the blue component runs into and breaks up around a solid continuum component. We see a distinct tail to the south-west for some transitions, consistent with features seen in the optical and near-infrared. We find that a significant fraction of TiO2 remains in the gas phase outside the dust-formation zone and suggest that this species might play only a minor role in the dust-condensation process around extreme oxygen-rich evolved stars like VY CMa.
Author
Elvire De Beck
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Wouter Vlemmings
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Sebastien Muller
Chalmers, Earth and Space Sciences, Onsala Space Observatory
John H Black
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
Eamon O Gorman
Chalmers, Earth and Space Sciences, Onsala Space Observatory
A.M.S. Richards
University of Manchester
A. Baudry
Laboratoire d'Astrophysique de Bordeaux
Matthias Maercker
Chalmers, Earth and Space Sciences, Onsala Space Observatory
L. Decin
University of Amsterdam
KU Leuven
E. M. Humphreys
European Southern Observatory (ESO)
Journal of Physics: Conference Series
17426588 (ISSN) 17426596 (eISSN)
Vol. 728 2 Art. no. UNSP 022009- 022009Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1088/1742-6596/728/2/022009