Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysis of Galactic Rotation from Masers based on a Nonlinear Oort
  Model   Based on data on Galactic masers with measured trigonometric parallaxes, we
have tested a nonlinear model of Galactic rotation using generalized Oort
formulas. This model is shown to yield pretty good results up to heliocentric
distances of 3--4 kpc. The main feature of the method is the possibility of
estimating the solar Galactocentric distance Ro. This distance has been found
by analyzing approximately 60 masers to be Ro=8.3+/-0.4 kpc. Our study of the
three-dimensional kinematics of more than 100 masers based on the
Ogorodnikov--Milne model has shown that significant nonlinearities are present
only in the xy plane (rotation around the Galactic z axis) due to the
peculiarities of the Galactic rotation curve. No significant linear dependences
have been found in the xz and yz planes. We show the presence of a wave in the
velocities w as a function of coordinate x or distance R with a wavelength of 3
kpc and an amplitude of 10 km/s. The wave is particularly prominent in the
Local and Perseus arms.

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The categories of this paper are: ao-sci
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The categories of this paper are: cmp-lg
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The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
3
The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org