Fermi LAT 4LAC-DR3: 3,407 Active Galactic Nuclei from 12 Years of Gamma-Ray Data

12 years of gamma-ray data above 50 MeV form the basis for this third update to the Fermi Large Area Telescope's fourth AGN catalog. The 4LAC-DR3 version contains 3,407 high-latitude active galactic nuclei with updated spectral parameters, energy distributions, and light curves. NASA HEASARC ingested the table in February 2010 and last updated it in June 2023 using data from the Fermi Science Support Center.

Use Cases

• Analyze gamma-ray spectral energy distributions (SEDs) based on updated spectral parameters.
• Study temporal variability of AGN emissions based on the updated yearly light curves.
• Perform population studies of high-latitude AGNs based on the catalog of 3,407 sources.
• Validate source associations and classifications based on the updated association data.

Strengths

• Contains 3,407 cataloged sources, providing a substantial sample for analysis.
• Based on 12 years of observational data, offering a long temporal baseline.
• Spectral parameters, SEDs, and light curves have been updated for all sources.
• Maintained and updated by NASA HEASARC, with a version update in June 2023.

Limitations

• Row count is unknown, which may limit suitability assessment.
• Column-level documentation is absent; field semantics must be inferred after download.
• Excludes low-latitude sources, which are provided in a separate file and not part of the formal catalog.

Provenance

Source

Fermi Science Support Center (FSSC), NASA HEASARC

Collection Method

Observational data from the Fermi Large Area Telescope (LAT).

Time Range

12 years of data collection (specific start/end years not provided).

Freshness

Last updated 2026-03-13 20:11:27.494578; freshness should be verified.

Geography

High Galactic latitudes (|b| > 10 degrees); celestial coverage.