Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Oscillations of MHD shock waves on the surfaces of T Tauri stars   This work treats the matter deceleration in a magnetohydrodynamics radiative
shock wave at the surface of a star. The problem is relevant to classical T
Tauri stars where infalling matter is channeled along the star's magnetic field
and stopped in the dense layers of photosphere. A significant new aspect of the
present work is that the magnetic field has an arbitrary angle with respect to
the normal to the star's surface. We consider the limit where the magnetic
field at the surface of the star is not very strong in the sense that the
inflow is super Alfv\'enic. In this limit the initial deceleration and heating
of plasma (at the entrance to the cooling zone) occurs in a fast
magnetohydrodynamic shock wave. To calculate the intensity of radiative losses
we use "real" and "power-law" radiative functions. We determine the
stability/instability of the radiative shock wave as a function of parameters
of the incoming flow: velocity, strength of the magnetic field, and its
inclination to the surface of the star. In a number of simulation runs with the
"real" radiative function, we find a simple criterion for stability of the
radiative shock wave. For a wide range of parameters, the periods of
oscillation of the shock wave are of the order 0.02-0.2 sec.

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The categories of this paper are: nucl-th
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin
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The categories of this paper are: stat
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ph
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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: chao-dyn
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The categories of this paper are: physics
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The categories of this paper are: alg-geom