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CGRO/EGRET Photon Lists and Maps

Metadata Updated: September 19, 2025

The Energetic Gamma-Ray Experiment Telescope (EGRET), which operated from 1991-April until 2000-May, was sensitive to photons in the energy range from about 30 MeV to over 20 GeV, the highest energies accessible by the CGRO instruments, and, like COMPTEL, was an imaging instrument. This catalog includes photon lists in qvp files, with one file for each EGRET viewing period. Photons which pass an energy-dependent cut on zenith angle (to exclude earth-albedo gamma rays) are processed into maps of photon counts for a standard set of energy ranges. Exposure and intensity (counts divided by exposure) maps are generated for each counts map. The counts maps typically include photons detected up to 40 degrees from the instrument axis. Most analysis has been done using data within 30 degrees of the instrument axis, where the point-spread function is narrower and the effective area greater than further off axis. All EGRET data files in the archive are the final versions, produced after the end of the mission. More detailed information about EGRET, EGRET data, and EGRET data analysis software can be found at: <pre> <a href="https://heasarc.gsfc.nasa.gov/docs/cgro/egret/egret_doc.html">https://heasarc.gsfc.nasa.gov/docs/cgro/egret/egret_doc.html</a>; </pre> The data contained in this database table was supplied by the CGRO Science Support Center. The contents this table was last updated in May 2001. Galactic coordinates were added to the table by the HEASARC in August 2005. 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.

Downloads & Resources

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/egretdata
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 6a19a1fc-757b-4896-8249-01febe8296cf
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://heasarc.gsfc.nasa.gov/W3Browse/all/egretdata.html
Program Code 026:000
Source Datajson Identifier True
Source Hash 56d10cd8cf28e3748d05b6a743d7a598a6a774929a73076962a9961aac5469cd
Source Schema Version 1.1

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