Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radio sources in the 2dF Galaxy Redshift Survey: AGN, starburst galaxies
  and their cosmic evolution   Radio continuum surveys can detect galaxies over a very wide range in
redshift, making them powerful tools for studying the distant universe. Until
recently, though, identifying the optical counterparts of faint radio sources
and measuring their redshifts was a slow and laborious process which could only
be carried out for relatively small samples of galaxies.
  Combining data from all-sky radio continuum surveys with optical spectra from
the new large-area redshift surveys now makes it possible to measure redshifts
for tens of thousands of radio-emitting galaxies, as well as determining
unambiguously whether the radio emission in each galaxy arises mainly from an
active nucleus (AGN) or from processes related to star formation. Here we
present some results from a recent study of radio-source populations in the 2dF
Galaxy Redshift Survey, including a new derivation of the local star-formation
density, and discuss the prospects for future studies of galaxy evolution using
both radio and optical data.

19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph