The Fermi-LAT collaboration has recently released an updated list of cosmic gamma-ray sources. The third release of the Fermi Point Source Catalog (4FGL-DR3) includes data from 12 years of observations by the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope. This updated catalog contains a total of 6658 sources in the energy range of 50 MeV to 1 TeV.
Among the gamma-ray sources in our own galaxy, pulsars are the most abundant, with approximately 300 detected. In contrast, the extragalactic sky is dominated by blazars and blazar candidates, which make up about 3700 sources. Compared to the previous catalog (which covered 8 years of data), the new release has identified around 1600 new sources. The proportion of these new sources aligns with the previous catalogs, with blazars and pulsars being the most common types.
Dario Gasparrini, a researcher at ASI Space Science Data Center and INFN Tor Vergata, noted that there are still many unidentified sources on the galactic plane. These sources have soft spectra and their nature is currently being investigated.
This updated version of the catalog provides improved spectral characterization for each source, extends the analysis up to 1 TeV, and updates light curves, spectral energy distributions, and associations for all sources in the catalog.
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