CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources

TL;DR

CRATES is a comprehensive all-sky survey at 8.4 GHz cataloging over 11,000 flat-spectrum radio sources with detailed positional and structural data, aiding in the identification of high-energy blazars and other radio sources.

Contribution

This work presents the first uniform, high-resolution all-sky catalog of flat-spectrum radio sources at 8.4 GHz, combining existing data with new observations.

Findings

Catalog contains ~11,000 sources with precise positions.

Identifies morphological and spectral properties of sources.

Enhances selection of high-energy blazars.

Abstract

We have assembled an 8.4 GHz survey of bright, flat-spectrum (alpha > -0.5) radio sources with nearly uniform extragalactic (|b|>10 deg) 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, sub-arcsecond 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.