Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High angular resolution ALMA images of dust and molecules in the SN
  1987A ejecta   We present high angular resolution (~80 mas) ALMA continuum images of the SN
1987A system, together with CO $J$=2 $\!\rightarrow\!$ 1, $J$=6
$\!\rightarrow\!$ 5, and SiO $J$=5 $\!\rightarrow\!$ 4 to $J$=7
$\!\rightarrow\!$ 6 images, which clearly resolve the ejecta (dust continuum
and molecules) and ring (synchrotron continuum) components. Dust in the ejecta
is asymmetric and clumpy, and overall the dust fills the spatial void seen in
H$\alpha$ images, filling that region with material from heavier elements. The
dust clumps generally fill the space where CO $J$=6 $\!\rightarrow\!$ 5 is
fainter, tentatively indicating that these dust clumps and CO are locationally
and chemically linked. In these regions, carbonaceous dust grains might have
formed after dissociation of CO. The dust grains would have cooled by
radiation, and subsequent collisions of grains with gas would also cool the
gas, suppressing the CO $J$=6 $\!\rightarrow\!$ 5 intensity. The data show a
dust peak spatially coincident with the molecular hole seen in previous ALMA CO
$J$=2 $\!\rightarrow\!$ 1 and SiO $J$=5 $\!\rightarrow\!$ 4 images. That dust
peak, combined with CO and SiO line spectra, suggests that the dust and gas
could be at higher temperatures than the surrounding material, though higher
density cannot be totally excluded. One of the possibilities is that a compact
source provides additional heat at that location. Fits to the
far-infrared--millimeter spectral energy distribution give ejecta dust
temperatures of 18--23K. We revise the ejecta dust mass to $\mathrm{M_{dust}} =
0.2-0.4$M$_\odot$ for carbon or silicate grains, or a maximum of
$<0.7$M$_\odot$ for a mixture of grain species, using the predicted
nucleosynthesis yields as an upper limit.

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The categories of this paper are: hep-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: bayes-an
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The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: physics