Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gas phase atomic metals in the circumstellar envelope of IRC+10216   We report the results of a search for gas phase atomic metals in the
circumstellar envelope of the AGB carbon star IRC+10216. The search was made
using high resolution (R=50000) optical absorption spectroscopy of a backgound
star that probes the envelope on a line of sight 35" from the center. The metal
species that we detect in the envelope include NaI, KI, CaI, CaII, CrI, and
FeI, with upper limits for AlI, MnI, TiI, TiII, and SrII. The observations are
used to determine the metal abundances in the gas phase and the condensation
onto grains. The metal depletions range from a factor of 5 for Na to 300 for
Ca, with some similarity to the depletion pattern in interstellar clouds. Our
results directly constrain the condensation efficiency of metals in a
carbon-rich circumstellar envelope and the mix of solid and gas phase metals
returned by the star to the ISM. The abundances of the uncondensed metal atoms
that we observe are typically larger than the abundances of the metal-bearing
molecules detected in the envelope. The metal atoms are therefore the major
metal species in the gas phase and likely play a key role in the metal
chemistry.

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The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org