COSMOS2020 Farmer Catalog: Photometry and Redshifts for 1.7 Million Sources

The COSMOS2020 Farmer Catalog from the National Aeronautics and Space Administration contains source detection and multi-wavelength photometry for 1.7 million sources in the 2 square degree COSMOS field. Approximately 966,000 sources have photometry from both traditional aperture methods and the new profile-fitting tool, The Farmer. Photometric redshifts are computed for all sources using two independent codes, LePhare and EAZY, achieving sub-percent precision for bright sources and 5% accuracy for the faintest.

Use Cases

• Training photometric redshift estimation models based on multi-wavelength photometry.
• Comparing galaxy properties across different photometric measurement techniques.
• Conducting large-scale statistical analyses of source populations in the COSMOS field.
• Benchmarking the performance of new photometric redshift codes against established methods.

Strengths

• Covers 1.7 million astronomical sources, providing a large sample for analysis.
• Photometry for approximately 966,000 sources is measured with two independent methods, allowing for cross-validation.
• Photometric redshifts are computed with two independent codes, LePhare and EAZY, enhancing reliability.
• Achieves sub-percent photometric redshift precision for sources brighter than i < 21 magnitude.

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 observational bias inherent to the specific 2 square degree COSMOS field.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Source detection and photometry performed on the COSMOS field using traditional aperture photometry and the profile-fitting tool, The Farmer.

Time Range

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Freshness

Last updated 2026-03-13 17:10:47.042433; freshness should be verified.

Geography

Covers the 2 square degree COSMOS field.