Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gas and stars in compact (young) radio sources   Gas can be used to trace the formation and evolution of galaxies as well as
the impact that the nuclear activity has on the surrounding medium. For nearby
compact radio sources, we have used observations of neutral hydrogen - that we
detected in emission distributed over very large scales - combined with the
study of the stellar population and deep optical images to investigate the
history of the formation of their host galaxy and the triggering of the
activity. For more distant and more powerful compact radio sources, we have
used optical spectra and HI - in absorption - to investigate the presence of
fast outflows that support the idea that compact radio sources are young radio
loud AGN observed during the early stages of their evolution and currently
shredding their natal cocoons through extreme circumnuclear outflows. We will
review the most recent results obtained from these projects.

21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg