Radio Sources in the Nearby Universe

Abstract

We identified 15,658 NRAO VLA Sky Survey (NVSS) radio sources among the 55,288 2 Micron All-Sky Survey eXtended (2MASX) galaxies brighter than k 20fe  = 12.25 at λ  = 2.16 μ m and covering the Ω = 7.016 sr of sky defined by J2000 δ  > −40° and . The complete sample of 15,043 galaxies with 1.4 GHz flux densities S  ≥ 2.45 mJy contains a 99.9% spectroscopically complete subsample of 9517 galaxies with k 20fe  ≤ 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 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 and in the universe today, and the spectroscopic subsample is large enough that the quoted errors are dominated by cosmic variance. The recent comoving star formation rate density indicated by U SF is .