1 research outputs found
Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars
Context. The recent detection of warm HO vapor emission from the outflows
of carbon-rich asymptotic giant branch (AGB) stars challenges the current
understanding of circumstellar chemistry. Two mechanisms have been invoked to
explain warm HO vapor formation. In the first, periodic shocks passing
through the medium immediately above the stellar surface lead to HO
formation. In the second, penetration of ultraviolet interstellar radiation
through a clumpy circumstellar medium leads to the formation of HO
molecules in the intermediate wind.
Aims. We aim to determine the properties of HO emission for a sample of
18 carbon-rich AGB stars and subsequently constrain which of the above
mechanisms provides the most likely warm HO formation pathway.
Methods, Results, and Conclusions. See paper