FRICAT: A FIRST catalog of FRI radio galaxies
  We built a catalog of 219 FRI radio galaxies (FRIs), called FRICAT, selected
from a published sample and obtained by combining observations from the NVSS,
FIRST, and SDSS surveys. We included in the catalog the sources with an
edge-darkened radio morphology, redshift $\leq 0.15$, and extending (at the
sensitivity of the FIRST images) to a radius $r$ larger than 30 kpc from the
center of the host. We also selected an additional sample (sFRICAT) of 14
smaller (10 $<r<$ 30 kpc) FRIs, limiting to $z<0.05$. The hosts of the FRICAT
sources are all luminous ($-21 \gtrsim M_r \gtrsim -24$), red early-type
galaxies with black hole masses in the range $10^8 \lesssim M_{\rm BH} \lesssim
3\times10^9 M_\odot$; the spectroscopic classification based on the optical
emission line ratios indicates that they are all low excitation galaxies.
Sources in the FRICAT are then indistinguishable from the FRIs belonging to the
Third Cambridge Catalogue of Radio Sources (3C) on the basis of their optical
properties. Conversely, while the 3C-FRIs show a strong positive trend between
radio and [OIII] emission line luminosity, these two quantities are unrelated
in the FRICAT sources; at a given line luminosity, they show radio luminosities
spanning about two orders of magnitude and extending to much lower ratios
between radio and line power than 3C-FRIs. Our main conclusion is that the
3C-FRIs just represent the tip of the iceberg of a much larger and diverse
population of FRIs.
