FRIICAT: A FIRST catalog of FR~II radio galaxies

Abstract

We built a catalog of 122 FR~II radio galaxies, called FRII{\sl{CAT}}, selected from a published sample obtained by combining observations from the NVSS, FIRST, and SDSS surveys. The catalog includes sources with redshift $\leq 0.15$, an edge-brightened radio morphology, and those with at least one of the emission peaks located at radius $r$ larger than 30 kpc from the center of the host. The radio luminosity at 1.4 GHz of the \FRII\ sources covers the range $L_{1.4} \sim 10^{39.5} - 10^{42.5}$ $\ergs$. The \FRII\ catalog has 90\% of low and 10\% of high excitation galaxies (LEGs and HEGs), respectively. The properties of these two classes are significantly different. The FRII{\sl{CAT}} LEGs are mostly luminous ($-20 \gtrsim M_r \gtrsim -24$), red early-type galaxies with black hole masses in the range $10^8 \lesssim M_{\rm BH} \lesssim 10^9 M_\odot$; they are essentially indistinguishable from the FR~Is belonging to the FRI{\sl{CAT}}. The HEG FR~IIs are associated with optically bluer and mid-IR redder hosts than the LEG FR~IIs and to galaxies and black holes that are smaller, on average, by a factor $\sim$2. FR~IIs have a factor $\sim$ 3 higher average radio luminosity than FR~Is. Nonetheless, most ($\sim 90$ \%) of the selected FR~IIs have a radio power that is lower, by as much as a factor of $\sim$100, than the transition value between FR~Is and FR~IIs found in the 3C sample. The correspondence between the morphological classification of FR~I and FR~II and the separation in radio power disappears when including sources selected at low radio flux thresholds, which is in line with previous results. In conclusion, a radio source produced by a low power jet can be edge brightened or edge darkened, and the outcome is not related to differences in the optical properties of the host galaxy.