VLA-COSMOS 3-GHz: Multiwavelength Counterparts for 9,161 Radio Sources

The COSMOS field, covering 2.6 square degrees, is the source for this catalog of 9,161 optical to mid-infrared counterparts for radio sources. The data originates from the VLA-COSMOS 3-GHz Large Project radio survey, combined with optical, infrared, and X-ray observations, and was created by the HEASARC. It classifies sources as star-forming galaxies or active galactic nuclei (AGN) based on luminosity, color, and spectral-energy distribution criteria.

Use Cases

• Classifying radio sources as star-forming galaxies or AGN based on X-ray luminosity and MIR color criteria.
• Analyzing the fractional contribution of different galaxy populations to the faint radio sky down to ~11 uJy flux levels.
• Extrapolating population fractions to predict the composition of samples for future SKA surveys.
• Studying high-redshift analogs to local low- and high-excitation AGN based on radiative luminosity.

Strengths

• Contains 9,161 counterparts with a high (~93%) match rate for the radio sample in unmasked areas.
• Covers a large, well-defined area of up to 2.35 square degrees from multiple catalogs (COSMOS2015, i-band, IRAC).
• Provides classification based on multiple, explicitly stated criteria including X-ray luminosity, MIR color, and SED.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is limited to the specific unmasked areas of the COSMOS field, excluding regions affected by bright sources.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Combined radio continuum survey data from the VLA with optical, near-infrared (UltraVISTA), mid-infrared (Spitzer/IRAC), and X-ray (Chandra) observations.

Time Range

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Freshness

Last updated 2026-03 13 19:47:46.767920; freshness should be verified.

Geography

COSMOS field, covering 2.6 square degrees.