Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Interferometric Observations of the Quiet Sun at 20 and 25 MHz in May
  2014   Results of solar observations at 20 and 25 MHz by the UTR-2
(\textit{Ukrainian T-shaped Radio telescope of the second modification}) radio
telescope in the interferometric session from 27 May to 2 June 2014 are
presented. In such a case the different baselines 225, 450, and 675 m between
sections of East--West and North--South arms of the radio telescope UTR-2 were
used. On 29 May 2014, strong sporadic radio emission consisting of Type III, a
Type II and a Type IV bursts was observed. On other days there was no solar
radio activity in the decameter range. We discuss the results of observations
of such the quiet Sun. Fluxes and sizes of the Sun in East--West and
North--South directions were measured. The average fluxes were 1050--1100 Jy
and 1480--1570 Jy at 20 and 25 MHz, respectively. Angular sizes of the quiet
Sun in equatorial and polar directions were 55' and 49' at 20 MHz and 50' and
42' at 25 MHz. Brightness temperatures of radio emission were Tb = 5.1 10^5 K
and Tb = 5.7 10^5 K at 20 and 25 MHz, respectively.

16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat