Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Search for Radio Continuum Emission Towards Long-period Variable Stars   We hereby report on a sensitive search for radio continuum observations from
a sample of 34 Mira and semi-regular variable stars. The main aim of this
survey was to search for thermal free-free emission from post-shock ionised
gas. Thirty-four stars were observed at 3- and 6-cm using the Australia
Telescope Compact Array. Radio continuum emission was detected from one source
only, the symbiotic Mira R Aqr. No continuum emission was detected from the
other sources, with three-sigma upper limits of typically 0.3 mJy. From the
upper limits to the radio flux densities, we have found upper limits to the gas
brightness temperatures near two stellar radii at a characteristic size of
$5\times10^{13}$ cm. Upper limits to shock velocities have been estimated using
a shock model. For the 11 nearest sources in our sample we obtain brightness
temperatures below 6 000 K and shock velocities below 13 km s$^{-1}$. For 11
out of 14 sources with previously published detections, the radio brightness
temperatures are below 4 000 K. For an upper limit of 4 000 K, we estimate that
the shock velocities at two stellar radii are below 10 km s$^{-1}$.

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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
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The categories of this paper are: q-bio
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
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The categories of this paper are: q-fin
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The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
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The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph