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Fermi LAT High-Energy Source Catalog (1FHL)

Metadata Updated: September 19, 2025

This table contains the catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first 3 years of the Fermi Gamma-ray Space Telescope mission. The first Fermi-LAT catalog of > 10 GeV sources (1FHL) has 514 sources. For each source, the authors present location, spectrum, a measure of variability,and associations with cataloged sources at other wavelengths. They found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, they find 20 (12) to have significant pulsations in the range > 10 GeV (> 25 GeV). In this work, the authors also report that, at energies above 10 GeV, unresolved sources account for 27% +/- 8% of the isotropic gamma-ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. The authors also highlight the subset of the 1FHL sources that are the best candidates for detection at energies above 50 - 100 GeV with current and future ground-based gamma-ray observatories. The time interval analyzed here is from the beginning of Fermi LAT science operations on 2008 August 4 (MET 239557447) to 2011 August 1 (MET 333849586), covering very nearly 3 years. In this work, the authors analyze gamma rays with energies in the range 10-500 GeV. To limit the contamination from gamma rays produced by cosmic-ray interactions in the upper atmosphere, gamma rays with zenith angles greater than 105 degrees were excluded. To further reduce the residual gamma rays from the upper atmosphere only data for time periods when the spacecraft rocking angle was less than 52 degrees were considered. See Section 2 of the reference paper for further explanations. This table was created by the HEASARC in April 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/209/34/">CDS Catalog J/ApJS/209/34/</a> files table3.dat and table7.dat. This is a service provided by NASA HEASARC .

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date April 11, 2025
Metadata Updated Date September 19, 2025
Publisher High Energy Astrophysics Science Archive Research Center
Maintainer
Identifier ivo://nasa.heasarc/fermilhesc
Data Last Modified 2025-09-10
Category Astrophysics
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id c98f0c03-32f3-41e8-954e-cc8082c01451
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/fermilhesc.html
Program Code 026:000
Source Datajson Identifier True
Source Hash bcde73d2d265108df34a0edd1c34db50ef708b7a7d550b73c19dffcc95b2bff0
Source Schema Version 1.1

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