SIMBAD references

A new 6 cm survey of almost 0.6 deg² to a limit of 0.55 mJy/beam (10 σ) finds 37 isolated radio sources and seven radio-source pairs (not necessarily physical companions). Infrared Array Camera (IRAC) counterparts are identified for at least 92% of the radio sources within the area of deep IRAC coverage, which includes 31 isolated sources and six pairs. This contrasts with an identification rate of <74% to R<23.95 in visible light. Eight of the IRAC galaxies have power-law spectral energy distributions, implying that the mid-infrared emission comes from a powerful active galactic nucleus (AGN). The remaining 26 IRAC galaxies show stellar emission in the mid-infrared, probably in most of these galaxies because the stellar emission is bright enough to outshine an underlying AGN. The infrared colors suggest that the majority of these galaxies are bulge-dominated and have redshifts 0.5≲z≲1. Visible spectra from the DEEP2 Redshift Survey, available for 11 galaxies, are consistent with this suggestion. The IRAC galaxies fall into two distinct groups in a color-magnitude diagram. One group (the ``stripe'') includes all the AGNs. The other group (the ``blue clump'') has blue 3.6-8 µm colors and a small range of 8 µm magnitudes. This separation should be useful in classifying galaxies found in other radio surveys.