Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Accretion flow in M87 is really MAD   The supermassive black holes in most galaxies in the universe are powered by
hot accretion flows. Both theoretical analysis and numerical simulations have
indicated that, depending on the degree of magnetization, black hole hot
accretion flow is divided into two modes, namely SANE (standard and normal
evolution) and MAD (magnetically arrested disk). It has been an important
question which mode the hot accretion flows in individual sources should belong
to in reality, SANE or MAD. This issue has been investigated in some previous
works but they all suffer from various uncertainties. By using the measured
rotation measure values in the prototype low-luminosity active galactic nuclei
in {M87} at 2, 5, and 8 GHz along the jet at various distances from the black
hole, combined with three dimensional general relativity magnetohydrodynamical
numerical simulations of SANE and MAD, we show in this paper that the predicted
rotation measure values by MAD are well consistent with observations, while the
SANE model overestimates the rotation measure by over two orders of magnitude
thus is ruled out.

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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
2
The categories of this paper are: math
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The categories of this paper are: ao-sci
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
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The categories of this paper are: nucl-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
1
The categories of this paper are: cs