- ID:
- ivo://nasa.heasarc/egrcat
- Title:
- CGRO/EGRET Revised Catalog of Gamma-Ray Sources
- Short Name:
- EGRCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The CGRO/EGRET Revised Catalog of Gamma-Ray Sources (EGR) is a catalog of point gamma-ray sources detected by the EGRET detector on the Compton Gamma Ray Observatory. The authors used the entire EGRET gamma-ray dataset of reprocessed photons at energies above 100 MeV and new Galactic interstellar emission models based on CO, H I, dark gas, and interstellar radiation field data. Two different assumptions are used to describe the cosmic-ray distribution in the Galaxy to analyse the systematic uncertainties in source detection and characterization. The authors applied a 2-dimensional maximum-likelihood detection method similar to that used to analyze the 3rd EGRET catalogue (3EG: Hartman et al. 1999, ApJS, 123, 79, available as the EGRET3 Catalog in Browse). The revised EGRET catalog (EGR) lists 188 sources, 14 of which are marked as confused, in contrast to the 271 entries of the 3rd EGRET (3EG) catalog. The authors do not detect 107 sources discovered previously because additional structure is present in the interstellar background. The vast majority of them were unidentified and marked as possibly extended or confused in the 3EG catalog. In particular, the authors do not confirm most of the 3EG sources associated with the local clouds of the Gould Belt. Alternatively, they have found 30 new sources that have no 3EG counterpart. The new error circles for the confirmed 3EG sources largely overlap the previous ones, but several counterparts of particular interest discussed before, such as Sgr A*, radio galaxies, and several microquasars are now found outside the error circles. The authors cross-correlated the source positions with a large number of radio pulsars, pulsar wind nebulae, supernova remnants, OB associations, blazars and flat radiosources and they found a surprising large number of sources (87) at all latitudes that have no counterpart among the potential gamma-ray emitters. Sources found within a radius of 1.5 PSF FWHM of a very bright source, and/or with very asymmetric TS map contours, are not included in the primary list of EGR sources but are included as EGRc sources herein. The EGRc sources represent significant excesses of photons above the background that may be due to extended sources, or structures not properly modeled in the interstellar emission, or artefacts due to incorrect PSF tails. As noted above, there are 188 sources in this catalog: since there are multiple measurements for these sources corresponding to the various viewing periods, there are 1640 entries in the HEASARC's version of the Revised EGRET Catalog, corresponding to 1512 'observations' of the 174 primary gamma-ray sources plus 128 'observations' of the 14 confused sources. Thus, there are an average of about 9 entries for every gamma-ray source. This table was created by the HEASARC in March 2009 based on the electronic versions of Tables A1 and B1 from the paper, which were obtained from the CDS, their catalog J/A+A/489/849 files egr.dat and egrc.dat. This is a service provided by NASA HEASARC .
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Search Results
- ID:
- ivo://nasa.heasarc/egret3
- Title:
- CGRO/EGRET Third Source Catalog
- Short Name:
- EGRET
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Third EGRET Catalog of High-Energy Gamma-Ray Sources is based on data obtained by the Energetic Gamma-Ray Experiment Telescope (EGRET) on board the Compton Gamma-Ray Observatory (CGRO) during the period from 1991 April 22 to 1995 October 3, corresponding to GRO Cycles 1, 2, 3, and 4. EGRET is 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, is an imaging instrument. In addition to including more data than the Second EGRET Catalog (2EG, Thompson et al. 1995, ApJS, 101, 259) and its supplement (2EGS, Thompson et al. 1996, ApJS, 107, 227), this catalog uses completely reprocessed data so as to correct a number of mostly minimal errors and problems. The 271 sources (E > 100 MeV) in the catalog include the single 1991 solar flare that was bright enough to detected as a source, the LMC, 5 pulsars, one probable radio galaxy detection (Cen A), and 66 high-confidence identifications of blazars (BL Lac objects, flat-spectrum radio quasars, or unidentified flat-spectrum radio sources). In addition, 27 lower-confidence potential blazar identifications are noted. Finally, the catalog contains 170 sources that are not yet firmly identified with known objects, although potential identifications have been suggested for a number of these. As already noted, there are 271 distinct sources in this catalog: since there are multiple measurements for these sources corresponding to the various viewing periods, there are 5246 entries in the HEASARC's version of the 3rd EGRET Catalog corresponding to the same number of lines in Table 4 of the published version. Thus, there are an average of about 20 entries for every distinct source. Notice that 14 sources reported in the 2nd EGRET Catalog or its supplement do not appear in this 3rd EGRET Catalog: 2EG J0403+3357, 2EG J0426+6618, 2EGS J0500+5902, 2EGS J0552-1026, 2EG J1136-0414, 2EGS J1236-0416, 2EG J1239+0441, 2EG J1314+5151, 2EG J1430+5356, 2EG J1443-6040, 2EG J1631-2845, 2EG J1709-0350, 2EG J1815+2950, and 2EG J2027+1054 due to the fact that the re-analysis of the EGRET data has dropped their statistical significance from just above the catalog threshold to just below it; additional information on these sources is provided in Table 5 of the published version of the 3rd EGRET Catalog. This database table was created by the HEASARC in June 1999, based on a machine-readable version of Table 4 of the 3rd EGRET Source Catalog that was provided by the CGRO Science Support Center (CGROSSC). Slight modifications to the Browse Object Classifications were later made in April 2001. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/osse
- Title:
- CGRO/OSSE Observations
- Short Name:
- OSSE
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table is based on the set of OSSE observation data products available at the HEASARC. The Oriented Scintillation Spectrometer Experiment (OSSE) is one of four experiments on NASA's Compton Gamma Ray Observatory (CGRO) satellite. OSSE was designed to undertake comprehensive gamma-ray observations of astrophysical sources in the 0.05-10 MeV energy range. The instrument also had secondary capabilities for gamma-ray and neutron observations above 10 MeV that are of particular value for solar flare studies. This database table was last updated in August 2005. Some duplicate entries in the table were removed in June 2019. The data in this table was supplied by the CGRO Science Support Center. This is a service provided by NASA HEASARC .
14. CGRO Timeline
- ID:
- ivo://nasa.heasarc/cgrotl
- Title:
- CGRO Timeline
- Short Name:
- CGROTL
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Compton Gamma-Ray Observatory (CGRO) was the second of NASA's Great Observatories. It was launched on April 5, 1991, from Space Shuttle Atlantis. It operated successfully for 9 years, and then was safely de-orbited and re-entered the Earth's atmosphere on June 4, 2000. Compton had four instruments that covered an unprecedented six decades of the electromagnetic spectrum, from 30 keV to 30 GeV. In order of increasing spectral energy coverage, these instruments were the Burst And Transient Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (CompTel), and the Energetic Gamma Ray Experiment Telescope (EGRET). BATSE viewed the full sky, as a transient monitor and is thus not included in this database table of pointed telescope observations. Also, EGRET and CompTel had wide fields of view, about 30 degrees, and, as such, viewed multiple targets per X-axis pointing. OSSE could be slewed (about one axis) independently from the spacecraft, so it typically viewed 2 targets per spacecraft Z-axis orientation, or "viewing period." Viewing periods were typically two weeks long. This database table contains the CGRO observations for Cycles 1 through 9. The Cycle 1 observations for EGRET and COMPTEL were part of the All-Sky Survey with no defined targets. This database table was last updated in November 2001. The information contained therein was provided by the Compton Observatory Science Support Center (COSSC). Galactic coordinates were added to the table by the HEASARC in August 2005. Duplicate entries in the table were removed in June 2019. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJ/563/80
- Title:
- 3906 gamma-ray bursts BATSE triggers
- Short Name:
- J/ApJ/563/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- During a scan of the archival BATSE daily records covering the entire 9.1yr (TJD 8369-11690) of the BATSE operation, 3906 gamma-ray bursts (GRBs) have been detected. 2068 of these GRBs are previously known BATSE triggers, while 1838 of them are new nontriggered bursts. It is important that all events were detected in the same type of data and were processed with the same procedure. Therefore these 3906 GRBs constitute a uniform sample. We have created a publicly available electronic data base (http://www.astro.su.se/groups/head/grb_archive.html) containing this sample. We describe the procedures of the data reduction, the selection of the GRB candidates, and the statistical tests for possible non-GRB contaminations. We also describe a novel test burst method used to measure the scan efficiency and the information obtained using the test bursts. Our scan decreases the BATSE detection threshold to ~0.1photon/s/cm2. As a first result, we show that the differential logN-logP distribution corrected for the detection efficiency extends to low brightnesses without any indication of a turnover. Any reasonable extrapolation of the new logN-logP to lower brightnesses imply a rate of several thousands of GRBs in the universe per year.
- ID:
- ivo://nasa.heasarc/gusbad
- Title:
- GRBs Uniformly Selected from BATSE Archival Data (Version 2.1)
- Short Name:
- BATSE/GUSBAD
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The GUSBAD (Gamma-ray bursts Uniformly Selected from BATSE Archival Data) Catalog is based on BATSE DISCLA data at a time resolution of 1.024 seconds for the full 9.1 years of the Compton Gamma-Ray Observatory (CGRO) mission from April 19, 1991 until May 26, 2000 (corresponding to Truncated Julian Dates from 8365 to 11690). This catalog lists over 2200 gamma-ray bursts (GRBs). Selection of GRBs for the GUSBAD Catalog requires a 5-sigma excess over the background in two of the BATSE detectors over the energy range 50-300 keV. The search covers the entire mission except when CGRO was over particular geographic regions or during one of 199,964 time windows when DISCLA data were missing or contaminated. The classification as GRB or non-GRB of the 6236 events that were produced by the software trigger was aided by correlating the times and positions of the events against the Current BATSE Burst Catalog. There are 589 GRBs in the GUSBAD Catalog that are not included in the Current BATSE Burst Catalog. The GUSBAD catalog is uniform in the sense that the detection criterion is the same throughout and that the properties given in the catalog are available for every burst. The detection and the derivation of the properties listed in the catalog were carried out automatically, except for some rare instances. This makes the catalog especially suitable for statistical work and simulations, such as used in the evaluation of V/Vmax. The procedure used to detect and classify the bursts has been described in Schmidt (2004). This database table was last updated by the HEASARC in April 2005 using the file GUSBADcat.dat containing version 2.1 of the catalog, which was obtained from the catalog author's web site at <a href="http://www.astro.caltech.edu/~mxs/grb/GUSBAD/">http://www.astro.caltech.edu/~mxs/grb/GUSBAD/</a> <p> Comments or questions about the contents of the GUSBAD Catalog are welcomed by the author who can be contacted at mxs@astro.caltech.edu. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/kommersgrb
- Title:
- Kommers et al. (2001) BATSE Non-Triggered Gamma-Ray Burst Catalog
- Short Name:
- Kommers
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is the Kommers et al. (2001) Non-Triggered Burst Supplement to the BATSE Gamma-Ray Burst (GRB) Catalog. It contains 873 "non-triggered" GRBs that were detected in a search of the BATSE Archival continuous data recorded between 1991 December 9 and 1997 December 17 for which the BATSE on-board burst trigger was not activated, for example because the burst was too faint to exceed the on-board detection threshold or it occurred while the on-board trigger was disabled for technical reasons. For each burst, the catalog gives an estimated source direction, duration, peak flux, and fluence. This catalog increases the number of GRBs detected using BATSE by 48% during the time period covered by the search. This database table was created at the HEASARC in September 2001 using the authors' file <a href="http://space.mit.edu/BATSE/ntgrb-ascii.html">http://space.mit.edu/BATSE/ntgrb-ascii.html</a> This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJ/481/95
- Title:
- Radio identification of EGRET sources
- Short Name:
- J/ApJ/481/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method to assess the reliability of the identification of EGRET sources with extragalactic radio sources. We verify that EGRET is detecting the blazar class of active galactic nuclei (AGNs). However many published identifications are found to be questionable. We provide a table of 42 blazars that we expect to be robust identifications of EGRET sources. This includes one previously unidentified EGRET source, the lensed AGN PKS 1830-210, near the direction of the Galactic center. We provide the best available positions for 16 more radio sources that are also potential identifications for previously unidentified EGRET sources. All high Galactic latitude EGRET sources (|b|>3) that demonstrate significant variability can be identified with flat-spectrum radio sources. This suggests that EGRET is not detecting any type of AGN other than blazars. This identification method has been used to establish with 99.998% confidence that the peak gamma-ray flux of a blazar is correlated with its average 5GHz radio flux. An even better correlation is seen between gamma-ray flux and the 2.29GHz flux density measured with VLBI at the base of the radio jet. Also, using high-confidence identifications, we find that the radio sources identified with EGRET sources have greater correlated VLBI flux densities than the parent population of flat radio spectrum sources.
- ID:
- ivo://nasa.heasarc/sterngrb
- Title:
- Stern et al. (2001) BATSE Gamma-Ray Burst Catalog
- Short Name:
- Stern
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Stern et al. (2001) BATSE Gamma-Ray Burst (GRB) Catalog was constructed by scanning the archival BATSE daily records (DISCLA data) covering the entire 9.1 years of BATSE's operation. 3906 GRBs were detected, 2068 of which are previously known BATSE triggers while 1838 of them are new non-triggered bursts. All events were detected in the same kind of data with 1.024 seconds time resolution and were processed with the same procedure, and thus constitute a uniform sample. This scan lowers the BATSE detection threshold to ~0.1 photons/s/cm**2. This database table was created at the HEASARC in August 2001 using the file <a href="ftp://ftp.astro.su.se/pub/head/grb/catalogs/etable2.txt">ftp://ftp.astro.su.se/pub/head/grb/catalogs/etable2.txt</a> on the Stockholm Observatory ftp site. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJS/107/227
- Title:
- Supplement to Second EGRET Catalog
- Short Name:
- J/ApJS/107/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This supplement extends the second EGRET catalog of high-energy gamma-ray sources (see recent paper by Thompson et al.), incorporating data from 1993 September to 1994 October. The second catalog contained 129 sources, based on data from 1991 April to 1993 September. An additional 28 sources are found, including three new identifications of active galactic nuclei.
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