Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Properties and short-time evolution of nearby galaxies   We analyze the results of processing of data of observations which had been
carried out with the VLBA during 10 last years. All the data have been
retrieved from archive of the National Radio Astronomy Observatory (USA NRAO,
Socorro, New Mexico). Particularly, we examine data of VLBA observational
sessions titled BK068, BL111, BL137, BL149, and BD086. Objects of our interest
are near galaxies with z < 0.02. The radio maps of compact structure around the
active galactic nuclei (AGN) reconstructed for two such galaxies (NGC315 and
3C274) in U frequency band (15 GHz) are presented. Some parameters of these
sources are shown in Table 1. We have to perform the careful amplitude and
phase calibration for all the data. Particularly, a correction of the delay
caused by the Earth atmosphere has been made because it is necessary in this
frequency range. Bright quasars close to the target sources (for instance,
J0136+4751 and 3C279 correspondingly) are used as atmosphere calibrators.
Secondly, the Multi Frequency Synthesis (MFS) method is used for final maps
reconstruction as well as for estimation of spectral index values of core and
jet of AGN of both objects. As a result, we can make some conclusions about the
milliarcsecond structure of central regions of sources thanks to the using of
these two methods of the VLBA data processing. Moreover, we can reveal some
changes of this structure in 1999 - 2009, and estimate roughly the velocities
and acceleration/deceleration values for brightest components of the nuclei of
NGC315 and 3C274. Any polarization phenomena are not taken into account. We
present results of processing of data of LL polarization for all the
observational sessions.

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The categories of this paper are: cs
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The categories of this paper are: eess
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
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The categories of this paper are: physics
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
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The categories of this paper are: hep-ph
9
The categories of this paper are: nlin