Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Outflow from Hot Accretion Flows   Numerical simulations of hot accretion flows have shown that the mass
accretion rate decreases with decreasing radius. Two models have been proposed
to explain this result. In the adiabatic inflow-outflow solution (ADIOS), it is
thought to be due to the loss of gas in outflows. In the convection-dominated
accretion flow (CDAF) model, it is explained as because that the gas is locked
in convective eddies. In this paper we use hydrodynamical (HD) and
magnetohydrodynamical (MHD) simulations to investigate which one is physical.
We calculate and compare various properties of inflow (gas with an inward
velocity) and outflow (gas with an outward velocity). Systematic and
significant differences are found. For example, for HD flows, the temperature
of outflow is higher than inflow; while for MHD flows, the specific angular
momentum of outflow is much higher than inflow. We have also analyzed the
convective stability of MHD accretion flow and found that they are stable.
These results suggest that systematic inward and outward motion must exist,
i.e., the ADIOS model is favored. The different properties of inflow and
outflow also suggest that the mechanisms of producing outflow in HD and MHD
flows are buoyancy associated with the convection and the centrifugal force
associated with the angular momentum transport mediated by the magnetic field,
respectively. The latter mechanism is similar to the Blandford & Payne
mechanism but no large-scale open magnetic field is required here. Possible
observational applications are briefly discussed.

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The categories of this paper are: nucl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
2
The categories of this paper are: math
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The categories of this paper are: hep-lat
3
The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con