Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Accelerating and Supersonic Density Fluctuations in Coronal Hole Plumes:
  Signature of Nascent Solar Winds   Slow magnetoacoustic waves in a static background provide a seismological
tool to probe the solar atmosphere in the analytic frame. By analyzing the
spatiotemporal variation of the electron number density of plume structure in
coronal holes above the limb for a given temperature, we find that the density
perturbations accelerate with supersonic speeds in the distance range from 1.02
to 1.23 solar radii. We interpret them as slow magnetoacoustic waves
propagating at about the sound speed with accelerating subsonic flows. The
average sonic height of the subsonic flows is calculated to be 1.27 solar
radii. The mass flux of the subsonic flows is estimated to be 44.1$\%$ relative
to the global solar wind. Hence, the subsonic flow is likely to be the nascent
solar wind. In other words, the evolution of the nascent solar wind in plumes
at the low corona is quantified for the first time from imaging observations.
Based on the interpretation, propagating density perturbations present in
plumes could be used as a seismological probe of the gradually accelerating
solar wind.

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn