Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The r-process in the neutrino-driven wind from a black-hole torus   We examine r-process nucleosynthesis in the neutrino-driven wind from the
thick accretion disk (or "torus") around a black hole. Such systems are
expected as emnants of binary neutron star or neutron star -- black hole
mergers. We consider a simplified, analytic, time-dependent evolution model of
a 3M_sun central black hole surrounded by a neutrino emitting accretion torus
with 90km radius, which serves as basis for computing spherically symmetric
neutrino-driven wind solutions. We find that ejecta with modest entropies (~30
per nucleon in units of the Boltzmann constant) and moderate expansion
timescales (~100ms) dominate in the mass outflow. The mass-integrated
nucleosynthetic abundances are in good agreement with the solar system
r-process abundance distribution if a minimal value of the electron fraction at
the charged-particle freezeout, Ye,min~0.2, is achieved. In the case of
Ye,min~0.3, the production of r-elements beyond A~130 does not reach to the
third peak but could be still important for an explanation of the abundance
signatures in r-process deficient stars in the early Galaxy. The total mass of
the ejected r-process nuclei is estimated to be ~1x10^-3 M_sun. If our model
was representative, this demands a Galactic event rate of ~2x10^-4 yr^-1 for
black-hole-torus winds from merger remnants to be the dominant source of the
r-process elements. Our result thus suggests that black-hole-torus winds from
compact binary mergers have the potential to be a major but probably not the
dominant production site of r-process elements.

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The categories of this paper are: solv-int
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
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The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: nlin