Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The formation of an inverse S-shaped active-region filament driven by
  sunspot motion and magnetic reconnection   We present a detailed study of the formation of an inverse S-shaped filament
prior to its eruption in active region NOAA 11884 from October 31 to November
2, 2013. In the initial stage, clockwise rotation of a small positive sunspot
around the main negative trailing sunspot formed a curved filament. Then the
small sunspot cancelled with negative magnetic flux to create a longer
active-region filament with an inverse S-shape. At the cancellation site a
brightening was observed in UV and EUV images and bright material was
transferred to the filament. Later the filament erupted after cancellation of
two opposite polarities under the upper part of the filament. Nonlinear
force-free field (NLFFF) extrapolation of vector photospheric fields suggests
that the filament may have a twisted structure, but this cannot be confirmed
from the current observations.

7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph