ALMA observations of TiO2 around VY CMa
Paper i 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.
Författare
Elvire De Beck
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
Wouter Vlemmings
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
Sebastien Muller
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
John H Black
Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik
Eamon O Gorman
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
A.M.S. Richards
University of Manchester
A. Baudry
Laboratoire d'Astrophysique de Bordeaux
Matthias Maercker
Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium
L. Decin
Universiteit Van 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- 022009Ämneskategorier
Astronomi, astrofysik och kosmologi
Fundament
Grundläggande vetenskaper
DOI
10.1088/1742-6596/728/2/022009