Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-equilibrium chemistry and dust formation in AGB stars as probed by
  SiO line emission   We have performed high spatial resolution observations of SiO line emission
for a sample of 11 AGB stars using the ATCA, VLA and SMA interferometers.
Detailed radiative transfer modelling suggests that there are steep chemical
gradients of SiO in their circumstellar envelopes. The emerging picture is one
where the radial SiO abundance distribution starts at an initial high
abundance, in the case of M-stars consistent with LTE chemistry, that
drastically decreases at a radius of ~1E15 cm. This is consistent with a
scenario where SiO freezes out onto dust grains. The region of the wind with
low abundance is much more extended, typically ~1E16 cm, and limited by
photodissociation. The surpisingly high SiO abundances found in carbon stars
requires non-equilibrium chemical processes.

18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph