Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Physical Basis of the Lx-Lbol Empirical Law for O-star X-rays   X-ray satellites since Einstein have empirically established that the X-ray
luminosity from single O-stars scales linearly with bolometric luminosity, Lx ~
10^-7 Lbol. But straightforward forms of the most favored model, in which
X-rays arise from instability-generated shocks embedded in the stellar wind,
predict a steeper scaling, either with mass loss rate Lx ~ Mdot ~ Lbol^1.7 if
the shocks are radiative, or with Lx ~ Lx ~ Mdot^2 ~ Lbol^3.4 if they are
adiabatic. We present here a generalized formalism that bridges these radiative
vs. adiabatic limits in terms of the ratio of the shock cooling length to the
local radius. Noting that the thin-shell instability of radiative shocks should
lead to extensive mixing of hot and cool material, we then propose that the
associated softening and weakening of the X-ray emission can be parametrized by
the cooling length ratio raised to a power m, the "mixing exponent." For
physically reasonable values m ~= 0.4, this leads to an X-ray luminosity Lx ~
Mdot^0.6 ~ Lbol that matches the empirical scaling. We conclude by noting that
such thin-shell mixing may also be important for X-rays from colliding wind
binaries, and that future numerical simulation studies will be needed to test
this thin-shell mixing ansatz for X-ray emission.

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The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
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The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph