Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Turbulence and magnetic spots at the surface of hot massive stars   Hot luminous stars show a variety of phenomena in their photospheres and in
their winds which still lack clear physical explanations at this time. Among
these phenomena are non-thermal line broadening, line profile variability
(LPVs), discrete absorption components (DACs), wind clumping and stochastically
excited pulsations. Cantiello et al. (2009) argued that a convection zone close
to the surface of hot, massive stars, could be responsible for some of these
phenomena. This convective zone is caused by a peak in the opacity due to iron
recombination and for this reason is referred as the "iron convection zone"
(FeCZ). 3D MHD simulations are used to explore the possible effects of such
subsurface convection on the surface properties of hot, massive stars. We argue
that turbulence and localized magnetic spots at the surface are the likely
consequence of subsurface convection in early type stars.

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The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: econ