GRO/EGRET ivo://nasa.heasarc/egretdata NASA/GSFC HEASARC HEASARC 2026-04-10 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Observation 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 . https://heasarc.gsfc.nasa.gov/W3Browse/all/egretdata.html Archive Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=egretdata& GET text/xml 180 99999 true 83.48 -72.26 30 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=egretdata GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_egretdata&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CGRO 30 Gamma-ray public egretdata CGRO/EGRET Photon Lists and Maps lii Galactic Longitude of the Pointing degree pos.galactic.lon double nullable start_time Date and Time of the Start of the Observation Start mjd time.start;obs double nullable end_time Date and Time of the Completion of the Observation mjd time.end;obs double nullable proposal_cycle Phase of the Operation obs.proposal.cycle short nullable vp Viewing Period meta.code;time.period short nullable "__row" System index column char nullable obsid Observation ID meta.id;meta.main char nullable "__z_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable wide_fov_flag FOV Flag: Y=Wide, N=Narrow meta.code;instr.fov char nullable "__x_ra_dec" System unit vector column double nullable dec Declination of the Pointing degree pos.eq.dec;meta.main double nullable ra Right Ascension of the Pointing degree pos.eq.ra;meta.main double nullable bii Galactic Latitude of the Pointing degree pos.galactic.lat double nullable