148GHz ACT extragalactic sources catalog

We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15mJy to 1500mJy. Comparison to other catalogs shows that 98% of the ACT detections correspond to sources detected at lower radio frequencies.

Three of the sources appear to be associated with the brightest cluster galaxies of low-redshift X-ray-selected galaxy clusters. Estimates of the radio to millimeter-wave spectral indices and differential counts of the sources further bolster the hypothesis that they are nearly all radio sources, and that their emission is not dominated by re-emission from warm dust. In a bright (>50mJy) 148GHz selected sample with complete cross-identifications from the Australia Telescope 20GHz survey, we observe an average steepening of the spectra between 5, 20, and 148GHz with median spectral indices of {alpha}_5-20_=-0.07+/-0.06, {alpha}_20-148_=-0.39+/-0.04, and {alpha}_5-148_=-0.20+/-0.03.