Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modelling the black hole silhouette in Sgr A* with ion tori   We calculate the "observed at infinity" image and spectrum of the accretion
structure in Sgr A*, by modelling it as an optically thin, constant angular
momentum ion torus in hydrodynamic equilibrium. The physics we consider
includes a two-temperature plasma, a toroidal magnetic field, as well as
radiative cooling by bremsstrahlung, synchrotron and inverse Compton processes.
Our relativistic model has the virtue of being fully analytic and very simple,
depending only on eight tunable parameters: the black hole spin and the
inclination of the spin axis to our line of sight, the torus angular momentum,
the polytropic index, the magnetic to total pressure ratio, the central values
of density and electron temperature and the ratio of electron to ion
temperatures. The observed image and spectrum are calculated numerically using
the ray-tracing code GYOTO. Our results demonstrate that the ion torus model is
able to account for the main features of the accretion structure surrounding
Sgr A*.

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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: cond-mat
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The categories of this paper are: dg-ga
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The categories of this paper are: ao-sci
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph
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The categories of this paper are: math
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The categories of this paper are: chem-ph