Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A persistent double nuclear structure in 3C 84   3C 84 (NGC 1275) is the radio source at the center of the Perseus Cluster and
exhibits a bright radio jet. We observed the source with the Global Millimeter
VLBI Array (GMVA) between 2008 and 2015, with a typical angular resolution of
$\sim$50 $\mu$as. The observations revealed a consistent double nuclear
structure separated by $\sim$770 gravitational radii assuming a Black Hole mass
of 3.2 $\times 10^{8}$ $M_{\odot}$. The region is likely too broad and bright
to be the true jet base anchored in the accretion disk or Black Hole
ergosphere. A cone and parabola were fit to the stacked (time averaged) image
of the nuclear region. The data did not strongly prefer either fit, but
combined with a jet/counter-jet ratio analysis, an upper limit on the viewing
angle to the inner jet region of $\leq$35$^{\circ}$ was found. This provides
evidence for a variation of the viewing angle along the jet (and therefore a
bent jet) within $\sim$0.5 parsec of the jet launching region. In the case of a
conical jet, the apex is located $\sim$2400 gravitational radii upstream of the
bright nuclear region and up to $\sim$600 gravitational radii upstream in the
parabolic case. We found a possible correlation between the brightness
temperature and relative position angle of the double nuclear components, which
may indicate rotation within the jet.

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The categories of this paper are: hep-ph
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The categories of this paper are: funct-an
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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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: hep-lat
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: atom-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: quant-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: adap-org
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The categories of this paper are: physics
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The categories of this paper are: alg-geom