New members in the gamma-ray zoo

New members in the gamma-ray zoo





The Fermi-LAT collaboration has published its fourth source catalog, named 4FGL. Based on eight years of data, it contains 5064 celestial objects emitting gamma rays at energies around 1 GeV, adding more than 2000 high-energy sources to the previous collection (published in 2015). More than one fourth of the objects are of unknown nature, calling for numerous follow-up studies. Although its volume is modest compared to the billions of sources listed in optical catalogs, the 4FGL catalog is by far the deepest in gamma-ray astronomy and serves as a reference to the entire domain. The catalog, coordinated by a researcher at the Astrophysics Department (AIM Laboratory) of CEA-Irfu at Paris-Saclay, is accessible on line at the NASA Fermi web site. In parallel, the 4LAC census of active galactic nuclei (coordinated by a researcher at CNRS/CENBG) is also made available to the community.