The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey
Creators: name: Marriage, T. A.
name: Juin, J. B.
name: Lin, Y. -T.
name: Marsden, D.
name: Nolta, M. R.
name: Partridge, B.
name: Ade, P. A. R.
name: Aguirre, P.
name: Amiri, M.
name: Appel, J. W.
name: Barrientos, L. F.
name: Battistelli, E. S.
name: Bond, J. R.
name: Brown, B.
name: Burger, B.
name: Chervenak, J.
name: Das, S.
name: Devlin, M. J.
name: Dicker, S. R.
name: Doriese, W. B.
name: Dunkley, J.
name: Dunner, R.
name: Essinger-Hileman, T.
name: Fisher, R. P.
name: Fowler, J. W.
name: Hajian, A.
name: Halpern, M.
name: Hasselfield, M.
name: Hernandez-Monteagudo, C.
name: Hilton, G. C.
name: Hilton, M.
name: Hincks, A. D.
name: Hlozek, R.
name: Huffenberger, K. M.
name: Hughes, D. H.
name: Hughes, J. P.
name: Infante, L.
name: Irwin, K. D.
name: Kaul, M.
name: Klein, J.
name: Kosowsky, A.
name: Lau, J. M.
name: Limon, M.
name: Lupton, R. H.
name: Martocci, K.
name: Mauskopf, P.
name: Menanteau, F.
name: Moodley, K.
name: Moseley, H.
name: Netterfield, C. B.
name: Niemack, M. D.
name: Page, L. A.
name: Parker, L.
name: Quintana, H.
name: Reid, B.
name: Sehgal, N.
name: Sherwin, B. D.
name: Sievers, J.
name: Spergel, D. N.
name: Staggs, S. T.
name: Swetz, D. S.
name: Switzer, E. R.
name: Thornton, R.
name: Trac, H.
name: Tucker, C.
name: Warne, R.
name: Wilson, G.
name: Wollack, E.
name: Zhao, Y.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report on extragalactic sources detected in a 455 square-degree map of the southern sky made with data at a frequency of 148 GHz from the Atacama Cosmology Telescope 2008 observing season. We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15 to 1500 mJy. 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 mm-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 (&gt;50 mJy) 148 GHz-selected sample with complete cross-identifications from the Australia Telescope 20 GHz survey, we observe an average steepening of the spectra between 5, 20, and 148 GHz with median spectral indices of $α_{\rm 5-20} = -0.07 \pm 0.06$, $α_{\rm 20-148} = -0.39 \pm0.04$, and $α_{\rm 5-148} = -0.20 \pm 0.03$. When the measured spectral indices are taken into account, the 148 GHz differential source counts are consistent with previous measurements at 30 GHz in the context of a source count model dominated by radio sources. Extrapolating with an appropriately rescaled model for the radio source counts, the Poisson contribution to the spatial power spectrum from synchrotron-dominated sources with flux density less than 20 mJy is $C^{\rm Sync} = (2.8 \pm 0.3) \times 10^{-6} \micro\kelvin^2$.
description: Accepted to ApJ