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

1742-6588 (ISSN)

Vol. 728 2 Art. no. UNSP 022009- 022009

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1088/1742-6596/728/2/022009

Mer information

Senast uppdaterat

2018-05-29