Radio Sources in the Nearby Universe

We identified 15,658 NVSS radio sources among the 55,288 2MASX galaxies brighter than $k_{20\mathrm{f}\mathrm{e}}=12.25$ at $\lambda =2.16\mu \mathrm{m}$ and covering the $\mathrm{\Omega }=7.016$ sr of sky defined by J2000 $\delta >-{40}^{\circ }$ and $\mathrm{\mid }b\mathrm{\mid }>{20}^{\circ }$. The complete sample of 15,043 galaxies with 1.4 GHz flux densities $S\ge 2.45\mathrm{m}\mathrm{J}\mathrm{y}$ contains a 99.9% spectroscopically complete subsample of 9,517 galaxies with $k_$20\mathrm{f}\mathrm{e}$ \leq 11.75$. We used only radio and infrared data to quantitatively distinguish radio sources powered primarily by recent star formation from those powered by active galactic nuclei. The radio sources with $\log[L($\mathrm{W}\mathrm{H}\mathrm{z}$^{-1})] > 19.3$ that we used to derive the local spectral luminosity and power-density functions account for $>99$% of the total 1.4~GHz spectral power densities $U_$\mathrm{S}\mathrm{F}$ = (1.54 \pm 0.20) \times 10^{19} $\mathrm{W}\mathrm{H}\mathrm{z}$^{-1} $\mathrm{M}\mathrm{p}\mathrm{c}$^{-3}$and$U_$\mathrm{A}\mathrm{G}\mathrm{N}$ = (4.23 \pm 0.78) \times 10^{19} $\mathrm{W}\mathrm{H}\mathrm{z}$^{-1} $\mathrm{M}\mathrm{p}\mathrm{c}$^{-3}$ in the universe today, and the spectroscopic subsample is large enough that the quoted errors are dominated cosmic variance. The recent comoving star-formation rate density indicated by $U_{\mathrm{S}\mathrm{F}}$ is $\psi \approx 0.015~ M_\odot $\mathrm{y}\mathrm{r}$^{-1} $\mathrm{M}\mathrm{p}\mathrm{c}$^{-3}$.