Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polarimetric analysis of STEREO observations of sungrazing Kreutz comet
  C/2010 E6 (STEREO)   Twin STEREO spacecraft pre-perihelion photometric and polarimetric
observations of the sungrazing Kreutz comet C/2010 E6 (STEREO) in March 2010 at
heliocentric distances $3-28 R_{\odot}$ were investigated using a newly-created
set of analysis routines. The comet fully disintegrated during its perihelion
passage. Prior to that, a broadening and an increase of the intensity peak with
decreasing heliocentric distance was accompanied by a drop to zero polarisation
at high phase angles (~105-135{\deg}, STEREO-B) and the emergence of negative
polarisation at low phase angles (~25-35{\deg}, STEREO-A). Outside the
near-comet region, the tail exhibited a steep slope of increasing polarisation
with increasing cometocentric distance, with the slope showing a marked
decrease with decreasing heliocentric distance. The steep slope is attributed
to sublimation of refractory organic matrix and the accompanied processing of
the fluffy aggregate dust grains, exposing silicates. The decrease in slope is
likely caused by the gradual sublimation of all refractory material closer to
the Sun, with resulting gases suppressing polarisation signal of the dust.
Near-zero polarisation closer to the comet head may be explained by the same
mechanism, stronger there due to the large amounts of material being ejected
and sublimated from the presumably disintegrating core, which correlates with
intensity data. Negative polarisation at small phase angles may be explained by
the presence of freshly ejected large silicate-rich aggregates. Despite both
zero and negative polarisation being observed simultaneously, the two
hypotheses on their causes are not easily reconciled. The need for further
studies of such comets, both observational and theoretical, is highlighted.

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The categories of this paper are: hep-ph
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The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
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The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph