ALMA observations of TiO2 around VY CMa
Paper in proceedings, 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- 022009

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.1088/1742-6596/728/2/022009

More information

Latest update

5/29/2018