AT20GDP: 20-GHz Radio Source Catalog for Deep Fields

85 radio sources detected in a 2009 deep survey covering 5 square degrees in the Chandra Deep Field South and SDSS Stripe 82. The catalog, created by NASA HEASARC in 2015, includes flux densities at 5.5, 9, 18, and 20 GHz, spectral indices, and notes on source variability over a 3-year period. The survey is estimated to be 90% complete above 2.5 mJy.

Use Cases

• Classifying radio sources as steep-spectrum or flat/inverted-spectrum based on spectral index measurements.
• Analyzing spectral curvature and identifying peaked-spectrum sources using multi-frequency flux densities.
• Studying source variability at 20 GHz over a 3-year timescale.
• Investigating the population of faint radio sources in well-studied deep extragalactic fields.

Strengths

• Includes 85 sources with detailed multi-frequency (5.5, 9, 18, 20 GHz) flux density measurements.
• Survey completeness is quantified as 90% above 2.5 mJy.
• Provides spectral indices and identifies 10 sources with clearly defined spectral peaks.
• Notes variability for at least 10 sources exceeding 15% at 20 GHz.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data may reflect geographic/temporal/source bias inherent to the specific survey fields and 2009 observation date.

Provenance

Source

NASA HEASARC, based on CDS Catalog J/MNRAS/439/1212.

Collection Method

Observations from the Australia Telescope Compact Array (ATCA) using the new CABB wide-bandwidth correlator in continuum mode.

Time Range

Observations were made in July 2009, with variability assessed over a 3-year timescale.

Freshness

Last updated 2026-03-13 16:33:40.597753; freshness should be verified.

Geography

Covers the Chandra Deep Field South and the Sloan Digital Sky Survey (SDSS) Stripe 82 region.