Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reassessment of an origin of the radio structure of J1420-0545   In this paper, we test the possibility that the structure of the largest
radio galaxy J1420-0545 may have been formed by restarted rather than primary
jet activity. This hypothesis was motivated by the unusual morphological
properties of the source consisting of two edge-brightened, narrow, highly
collinear, and symmetric lobes, thus suggesting an almost ballistic propagation
of powerful jets into a particularly low-density external medium. New
observations made with the VLA together with the currently available GLEAM and
TGSS ADR1 data releases allow the detection of an excess emission at low
frequencies. An extracted part (88 MHz - 200 MHz) of the spectrum of the
emission is fitted with the DYNAGE model, giving a forecast for the
environmental conditions and the energetic requirements for the presumed old
cocoon related to a preceding epoch of jet activity.

23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th