The Atacama Cosmology Telescope: Extragalactic sources at 148GHz in the 2008 survey

Tobias A. Marriage, Jean Baptiste Juin, Yen Ting Lin, Danica Marsden, Michael R. Nolta, Bruce Partridge, Peter A.R. Ade, Paula Aguirre, Mandana Amiri, John William Appel, L. Felipe Barrientos, Elia S. Battistelli, John R. Bond, Ben Brown, Bryce Burger, Jay Chervenak, Sudeep Das, Mark J. Devlin, Simon R. Dicker, W. Bertrand DorieseJoanna Dunkley, Rolando Dünner, Thomas Essinger-Hileman, Ryan P. Fisher, Joseph W. Fowler, Amir Hajian, Mark Halpern, Matthew Hasselfield, Carlos Hernndez-Monteagudo, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renée Hlozek, Kevin M. Huffenberger, David Handel Hughes, John P. Hughes, Leopoldo Infante, Kent D. Irwin, Madhuri Kaul, Jeff Klein, Arthur Kosowsky, Judy M. Lau, Michele Limon, Robert H. Lupton, Krista Martocci, Phil Mauskopf, Felipe Menanteau, Kavilan Moodley, Harvey Moseley, Calvin B. Netterfield, Michael D. Niemack, Lyman A. Page, Lucas Parker, Hernan Quintana, Beth Reid, Neelima Sehgal, Blake D. Sherwin, Jon Sievers, David N. Spergel, Suzanne T. Staggs, Daniel S. Swetz, Eric R. Switzer, Robert Thornton, Hy Trac, Carole Tucker, Ryan Warne, Grant Wilson, Ed Wollack, Yue Zhao

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60 Scopus citations


We report on extragalactic sources detected in a 455 deg2 map of the southern sky made with data at a frequency of 148GHz from the Atacama Cosmology Telescope (ACT) 2008 observing season. We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15 mJy 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 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 (>50 mJy) 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 α5-20 = -0.07 ± 0.06, α20-148 = -0.39 ± 0.04, and α5-148 = -0.20 ± 0.03. When the measured spectral indices are taken into account, the 148GHz 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 Sync = (2.8 ± 0.3) × 10-6μK 2.

Original languageEnglish (US)
Article number100
JournalAstrophysical Journal
Issue number2
StatePublished - Apr 20 2011

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • cosmic background radiation
  • galaxies: active
  • radio continuum: galaxies
  • surveys


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