3FHL: The Third Catalog of Hard Fermi-LAT Sources

By M. Ajello, W. Atwood, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, R. Bellazzini, E. Bissaldi, R. Blandford, E. Bloom and 125 more. 2017

314 citations recorded by the source corpus.

We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. This is the Third Catalog of Hard Fermi-LAT Sources (3FHL), containing 1556 objects characterized in the 10 GeV–2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog at the same energies (1FHL). The vast majority of detected sources (79%) are associated with extragalactic counterparts at other wavelengths, including 16 sources located at very high redshift (z > 2). Of the sources, 8% have Galactic counterparts and 13% are unassociated (or associated with a source of unknown nature). The high-latitude sky and the Galactic plane are observed with a flux sensitivity of 4.4 to 9.5 × 10−11 ph cm−2 s−1, respectively (this is approximately 0.5% and 1% of the Crab Nebula flux above 10 GeV). The catalog includes 214 new γ-ray sources. The substantial increase in the number of photons (more than 4 times relative to 1FHL and 10 times to 2FHL) also allows us to measure significant spectral curvature for 32 sources and find flux variability for 163 of them. Furthermore, we estimate that for the same flux limit of 10−12 erg cm−2 s−1, the energy range above 10 GeV has twice as many sources as the range above 50 GeV, highlighting the importance, for future Cherenkov telescopes, of lowering the energy threshold as much as possible.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/b91f1584780ab9518e6234bb0b496e8dddc5c51d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A (2018, background): “Sources (3FHL) (24) source catalogs, including the identified positionally”
The Search for Spatial Extension in High-latitude Sources Detected by the Fermi Large Area Telescope (2018, background): “It has discovered a wealth of γ-ray sources, culminating in the two most recent γ-ray source catalogs: the Fermi Third Source Catalog(3FGL, Acero et al. 2015) and Third Hard-Source Catalog (3FHL, Ajello et al. 2017).”
Fermi Large Area Telescope Fourth Source Catalog (2019, methodology): “The latest compilation of extended Fermi-LAT sources prior to this work consists of the 55 extended sources entered in the 3FHL catalog of sources above 10GeV (Ajello et al. 2017).”
Incremental Fermi Large Area Telescope Fourth Source Catalog (2022, background): “Thanks to the increased statistics after 12 yr (particularly valuable at high energy where the precision is limited by counts rather than background), we can provide them over eight energy bands in DR3, extending to 1 TeV as in the 3FHL catalog (Ajello et al. 2017).”
The First LHAASO Catalog of Gamma-Ray Sources (2023, unknown): “3+04.5 (Ajello et al. 2017).”