- ID:
- ivo://nasa.heasarc/egret3
- Title:
- CGRO/EGRET Third Source Catalog
- Short Name:
- EGRET
- Date:
- 10 May 2024
- 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 .
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- 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://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://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.
- ID:
- ivo://CDS.VizieR/J/ApJS/134/385
- Title:
- Supplement to the BATSE gamma-ray burst catalogs
- Short Name:
- J/ApJS/134/385
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory detects gamma-ray bursts (GRBs) with a real-time burst detection (or "trigger") system running on-board the spacecraft. Under some circumstances, however, a GRB may not activate the on-board burst trigger. For example, the burst may be too faint to exceed the on-board detection threshold, or it may occur while the on-board burst trigger is disabled for technical reasons. This paper describes a catalog of 873 "nontriggered" GRBs that were detected in a search of the archival continuous data from BATSE recorded between 1991 December 9.0 and 1997 December 17.0. For each burst, the catalog gives an estimated source direction, duration, peak flux, and fluence. Similar data are presented for 50 additional bursts of unknown origin that were detected in the 25-50keV range; these events may represent the low-energy "tail" of the GRB spectral distribution. This catalog increases the number of GRBs detected with BATSE by 48% during the time period covered by the search.
- ID:
- ivo://CDS.VizieR/J/ApJS/208/21
- Title:
- The BATSE 5B GRB spectral catalog
- Short Name:
- J/ApJS/208/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present systematic spectral analyses of gamma-ray bursts (GRBs) detected with the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory during its entire nine years of operation. This catalog contains two types of spectra extracted from 2145 GRBs, and fitted with five different spectral models resulting in a compendium of over 19000 spectra. The models were selected based on their empirical importance to the spectral shape of many GRBs, and the analysis performed was devised to be as thorough and objective as possible. We describe in detail our procedures and criteria for the analyses, and present the bulk results in the form of parameter distributions. This catalog should be considered an official product from the BATSE Science Team, and the data files containing the complete results are available from the High-Energy Astrophysics Science Archive Research Center (HEASARC).
- ID:
- ivo://CDS.VizieR/IX/20A
- Title:
- The Fourth BATSE Burst Revised Catalog
- Short Name:
- IX/20A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the fourth catalogue of the BATSE instrument on board of the Compton Gamma-ray Observatory (CGRO), launched on April 5, 1991. It contains the locations and times for 1637 triggered gamma-ray bursts (nominal energy range 50-300keV) observed from 19 April, 1991 until 29 August, 1996. This 4Br version has been revised from the version first circulated on CD-ROM in September 1997 (4B, file "4b.dat") to include improved locations for a subset of bursts that have been reprocessed using additional data. The Interplanetary Network (IPN) localization information for 147 gamma-ray bursts observed by the Burst and Transient Source Experiment between the end of the Third BATSE catalog and the end of the Fourth BATSE catalog, obtained by analyzing the arrival times of these bursts at the Ulysses and Compton Gamma-Ray Observatory (CGRO) spacecraft. are included in the table "ulysses.dat". Bursts found later (1607 triggers until 9 September 2000) are included in the file "grb.dat"; the data related to these events (those having a TrigNo>=5589) should be considered as preliminary. The Exposure table and Trigger Criteria tables are not included here; please consult the statistical results on the BATSE pages (http://gammaray.msfc.nasa.gov/batse/)
- ID:
- ivo://CDS.VizieR/J/ApJS/101/259
- Title:
- The second EGRET catalog
- Short Name:
- J/ApJS/101/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The second catalog of high-energy gamma-ray observations from the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory includes data from Phase 1 (1991 April - 1992 November) and Phase 2 (1992 November - 1993 September) of the mission. In addition to including more data than the first EGRET catalog (1994ApJS...94..551F), this catalog uses an improved model of the diffuse galactic gamma radiation. The 129 sources in the catalog include one solar flare bright enough to be detected as a source, the Large Magellanic Cloud, five pulsars, 40 high-confidence identifications of active galactic nuclei, 11 AGN identifications with lower confidence, and 71 sources not yet identified with known objects. Also included a re approximate upper limits for gamma-ray sources at any point in the sky and information about sources listed in the first EGRET catalog but not appearing in this one. The main catalog (table 4) was revised slightly after the preprint was made.
- ID:
- ivo://CDS.VizieR/J/ApJS/123/79
- Title:
- Third EGRET catalog (3EG)
- Short Name:
- J/ApJS/123/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The third catalog of high-energy gamma-ray sources detected by the EGRET telescope on the Compton Gamma Ray Observatory (3EG) includes data from 1991 April 22 to 1995 October 3 (cycles 1, 2, 3, and 4 of the mission). In addition to including more data than the second EGRET catalog and its supplement, this catalog uses completely reprocessed data to correct a number of mostly minimal errors and problems. 14 sources (3 from the Supplement) listed in Table 6 below are not appearing in the 3EG. The 271 sources (E>100 MeV) in the catalog include the single 1991 solar flare bright enough to be detected as a source, the Large Magellanic Cloud, five 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 not yet identified firmly with known objects, although potential identifications have been suggested for a number of those. This catalog supersedes the 2EG (Cat. <J/ApJS/101/259>) and its supplement (Cat. <J/ApJS/107/227>).