Crates: An all-sky survey of flat-spectrum radio sources

Stephen E. Healey, Roger W. Romani, Gregory B. Taylor, Elaine M. Sadler, Roberto Ricci, Tara Murphy, James S. Ulvestad, Joshua N. Winn

Research output: Contribution to journalArticlepeer-review

333 Scopus citations


We have assembled an 8.4 GHz survey of bright, flat-spectrum (a > -0.5) radio sources with nearly uniform extragalactic (|b| > 10°) coverage for sources brighter than S 4.8 GHz = 65 mJy. The catalog is assembled from existing observations (especially CLASS and the Wright et al. PMN-CA survey), augmented by reprocessing of archival VLA and ATCA data and by new observations to fill in coverage gaps. We refer to this program as CRATES, the Combined Radio All-Sky Targeted Eight GHz Survey. The resulting catalog provides precise positions, subarcsecond structures, and spectral indices for some 11,000 sources. We describe the morphology and spectral index distribution of the sample and comment on the survey's power to select several classes of interesting sources, especially high-energy blazars. Comparison of CRATES with other high-frequency surveys also provides unique opportunities for identification of high-power radio sources.

Original languageEnglish (US)
Pages (from-to)61-71
Number of pages11
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Jul 2007
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Galaxies: active
  • Quasars: general
  • Surveys


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