  Analysis of the frequency and physical properties of galaxies with
star-formation and AGN activity in different environments in the local universe
is a cornerstone for understanding structure formation and galaxy evolution. We
have built a new multiwavelength catalog for galaxies in a complete redshift
survey (the 15R Survey), gathering information on their H-alpha, R-band, radio,
far-infrared, and X-ray emission, as well as their radio and optical
morphologies, and have developed a classification scheme to compare different
selection methods and to select accurately samples of radio emitting galaxies
with AGN and star-forming activity. While alternative classification schemes do
not lead to major differences for star-forming galaxies, we show that
spectroscopic and photometric classifications of AGN lead to incomplete
samples. In particular, a large population of AGN-containing galaxies with
absorption-line spectra, and in many cases extended radio structures (jets,
lobes), is missed in the standard Baldwin-Phillips-Terlevich emission-line
classification of active galaxies. This missed class of objects accounts for
roughly half of the radio AGN population. Similarly, for X-ray selected AGN in
our sample, we find that absorption-line AGN account for half of the sample.
Spectroscopically unremarkable, passive galaxies with AGN activity are not an
exception, but the norm, and we show that although they exist in all
environments, these systems preferentially reside in higher density regions.
Because of the existence of this population, the fractional abundance of AGN
increases with increasing density, in contrast to some published results based
on emission-line AGN extracted from the 15R, Sloan and 2DF redshift surveys.
