Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The recurrent nuclear activity of Fornax A and its interaction with the
  cold gas   Sensitive (noise $\sim 16\,\mu$\Jyb), high-resolution ($\sim 10''$) MeerKAT
observations of Fornax A show that its giant lobes have a double-shell
morphology, where dense filaments are embedded in a diffuse and extended
cocoon, while the central radio jets are confined within the host galaxy. The
spectral radio properties of the lobes and jets of Fornax A reveal that its
nuclear activity is rapidly flickering. Multiple episodes of nuclear activity
must have formed the radio lobes, for which the last stopped $12$ Myr ago. More
recently ($\sim 3$ Myr ago), a less powerful and short ($\lesssim 1$ Myr) phase
of nuclear activity generated the central jets. The distribution and kinematics
of the neutral and molecular gas in the centre give insights on the interaction
between the recurrent nuclear activity and the surrounding interstellar medium.

25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
16
The categories of this paper are: stat
2
The categories of this paper are: math