| Main Search Form | List of GAMMA-RAY-BURSTS Catalogs |
 |
| Main Search Form | List of GAMMA-RAY-BURSTS Catalogs |
|
This table lists all of the spectroscopy results of gamma-ray bursts observed by a subset of the 8 BATSE Large Area Detectors. BATSE consisted, in part, of an array of 8 sodium iodide Large Area Detectors (LADs) which covered the energy range from ~20 keV - 2 MeV. The LAD detectors were placed at each of the eight corners of the CGRO spacecraft with an outward orientation such that the entire sky not occulted by the Eartt was observed. The spectrum files ("scat" files) available as FITS-format data products associated with this catalog provide parameter values and goodness-of-fit measures for different types of spectral fits and models. These fits are performed using 14-channel data, usually 2-second resolution CONT data. There are currently two spectrum categories:
* Peak flux ('pflx') - a single spectrum over a 2.05-second time range at the
peak flux of the burst
* Fluence ('flnc') - a single spectrum over the entire burst duration
The quoted fluxes and fluences are for the 20 keV - 2 MeV energy range,
notice. The scat files have two extensions. The first extension gives
detector-specific information, including photon fluxes and fluences for each
detector, which are provided for each energy channel. The second extension
provides derived quantities such as flux, fluence and model parameters for
the joint fit of all included detectors. The scat files and their
energy-resolved quantities contained in these two extensions will be
available soon in the HEASARC data archive. Quantities derived from these
spectral fits are available in the present table, as described below and in
the Goldstein et al. (2013) reference paper.
The spectra are fit with a number of models, with the signal-to-noise ratio of the spectrum often determining whether a more complex model is statistically favored. The current set is:
* Power law ('plaw'),
* Comptonized (exponentially attenuated power law; 'comp')
* Band ('band')
* Smoothly broken power law ('sbpl')
* Log_10 Gaussian ('glog')
The full details of these models are presented in Section 4 of the reference
paper.
The type of spectrum and spectral model are coded into the parameter names (and the associated file names) using the acronyms given above. Thus for example, the parameters with names beginning with 'flnc_glog' contain the results from fits to the fluence spectra using Log10 Gaussian models. The corresponding spectrum file for the burst with trigger number 105 with the results from a fit to the fluence spectrum using a Log10 Gaussian model is named scat_0105_flnc_glog_v00.fit.
Please note that this table lists the raw results of each spectral fit to each GRB. In cases where the spectral fit failed, the values reported are those that initialized the spectral fit. If the uncertainty on the spectral parameters is reported as zero (no uncertainty), then the fit failed. In a few cases throughout this table, the uncertainties for certain spectral parameters may be reported as '9999.99' which indicates that the uncertainty on that parameter is completely unconstrained. An example of this is when the spectral data from a burst is fitted with a BAND function but is unable to constrain the high-energy index. In this case, the best fit centroid value of the high-energy index parameter is reported, and the '9999.99' value is reported for the uncertainty.
Bursts since the end of the 1B catalog (March 1992) occurred when the Compton Gamma-Ray Observatory (CGRO) tape recorders were experiencing numerous errors. Consequently, there are gaps in the data of many bursts that preclude valid measurement of peak flux, peak rate, fluence, or duration. Peak rates on the 1 second timescale from each detector are almost always available. These data (called MAXBC rates) can be used to determine burst location. Previous difficulties with this data type have been largely removed, and we now believe that the systematic errors for MAXBC-located bursts are the same as for bursts located with other data types. It is still true however, that the MAXBC-located bursts usually have larger statistical errors than would be the case if another data type were available. The parameter called comments_position in this database contains comments on MAXBC-located bursts. A number of CGRO and BATSE flight software changes have significantly reduced the problem of data gaps since March of 1993.
All BATSE trigger data from the CGRO mission are available through this facility. As part of a final archiving effort, the BATSE instrument team is making minor refinements to certain data products. These revised products will be delivered to the HEASARC as soon as they are produced and tested. Certain burst catalog parameters, notably the position information, may be revised through improved analyses and instrumental calibration. The final catalog will be posted here as soon as it is completed.
This table lists all of the triggers observed by a subset of the 14 GBM detectors (12 NaI and 2 BGO) which have been classified as gamma-ray bursts (GRBs). Note that there are two Browse catalogs resulting from GBM triggers. All GBM triggers are entered in the Fermi GBM Trigger Catalog, while only those triggers classified as bursts are entered in the Burst Catalog. Thus, a burst will be found in both the Trigger and Burst Catalogs. The Burst Catalog analysis requires human intervention; therefore, GRBs will be entered in the Trigger Catalog before the Burst Catalog. The latency requirements are 1 day for triggers and 3 days for bursts. There are four fewer bursts in the online catalog than in the Gruber et al. 2014 paper. The four missing events (081007224, 091013989, 091022752, and 091208623) have not been classified with certainty as GRBs and are not included in the general GRB catalog. This classification may be revised at a later stage.
The GBM consists of an array of 12 sodium iodide (NaI) detectors which cover the lower end of the energy range up to 1 MeV. The GBM triggers off of the rates in the NaI detectors, with some Terrestrial Gamma-ray Flash (TGF)-specific algorithms using the bismuth germanate (BGO) detectors, sensitive to higher energies, up to 40 MeV. The NaI detectors are placed around the Fermi spacecraft with different orientations to provide the required sensitivity and FOV. The cosine-like angular response of the thin NaI detectors is used to localize burst sources by comparing rates from detectors with different viewing angles. The two BGO detectors are placed on opposite sides of the spacecraft so that all sky positions are visible to at least one BGO detector.
The signals from all 14 GBM detectors are collected by a central Data Processing Unit (DPU). This unit digitizes and time-tags the detectors' pulse height signals, packages the resulting data into several different types for transmission to the ground (via the Fermi spacecraft), and performs various data processing tasks such as autonomous burst triggering.
The GRB science products are transmitted to the FSSC in two types of files. The first file, called the "bcat" file, provides basic burst parameters such as duration, peak flux and fluence, calculated from 8-channel data using a spectral model which has a power-law in energy that falls exponentially above an energy EPeak, known as the Comptonized model. The crude 8-channel binning and the simple spectral model allow data fits in batch mode over numerous time bins in an efficient and robust fashion, including intervals with little or no flux, yielding both values for the burst duration, and deconvolved lightcurves for the detectors included in the fit. The bcat file includes two extensions. The first, containing detailed information about energy channels and detectors used in the calculations, is detector-specific, and includes the time history of the deconvolved flux over the time intervals of the burst. The second shows the evolution of the spectral parameters obtained in a joint fit of the included detectors for the model used, usually the Comptonized model described above. The bcat files and their time-varying quantities contained in these two extensions are available at the HEASARC FTP site. Quantities derived from these batch fits are given in the bcat primary header and presented in the Browse table, as described below. The main purpose of the analysis contained in the bcat file is to produce a measure of the duration of the burst after deconvolving the instrument response. The duration quantities are:
* 't50' - the time taken to accumulate 50% of the burst fluence starting at the 25% fluence level. * 't90' - the time taken to accumulate 90% of the burst fluence starting at the 5% fluence level.By-products of this analysis include fluxes on various timescales and fluences, both obtained using the simple Comptonized model described above. These quantities are detailed in the Browse table using the following prefixes:
* 'flux' - the peak flux over 3 different timescales obtained in the batch mode fit used to calculate t50/t90. * 'fluence' - the total fluence accumulated in the t50/t90 calculation.The fluxes and fluences derived from the 8-channel data for these bcat files should be considered less reliable than those in the spectral analysis files described below.
Analysis methods used in obtaining these quantities are detailed in the first GBM GRB Catalog (Paciesas et al. 2011). Updates of bcat files will be sent (with new version numbers) as these parameters are refined. This "bcat" file is produced for triggers that are classified as GRBs (with exceptions as described below), and supplements the initial data in the trigger or "tcat" file that is produced for all triggers.
The second type of file (the spectrum or "scat" file) provides parameter values and goodness-of-fit measures for different types of spectral fits and models. These fits are performed using 128-channel data, either CSPEC or, for short bursts, TTE data. The type and model are coded into the file name. There are currently two spectrum categories:
* Peak flux ('pflx') - a single spectrum over the time range of the peak flux of the burst
* Fluence ('flnc') - a single spectrum over the entire burst duration selected by the duty scientist.
Like the bcat files, the scat files have two extensions. The first extension
gives detector-specific information, including photon fluxes and fluences for
each detector, which are provided for each energy channel. The second
extension provides derived quantities such as flux, fluence and model
parameters for the joint fit of all included detectors. The scat files and
their energy-resolved quantities contained in these two extensions are
available in the Fermi data archive at the HEASARC. Quantities derived from
these spectral fits are available in the Browse table, as described below
and in Goldstein et al. (2011).
The spectra are fit with a number of models, with the signal-to-noise ratio of the spectrum often determining whether a more complex model is statistically favored. The current set is:
* Power law ('plaw'),
* Comptonized (exponentially attenuated power law; 'comp')
* Band ('band')
* Smoothly broken power law ('sbpl')
Warnings
The bcat and scat files result from two completely independent analyses, and consequently, it is possible that the same quantities might show differences. Indeed,
1) the fluxes and fluences in the "scat" files should be considered more reliable than those in the "bcat" files, with the official fluxes and fluences being those yielded by the statistically favored model ("Best_Fitting_Model" in the Browse table) and with the full energy resolution of the instrument;
2) in both the bcat and scat analyses, the set of detectors used for the fits ("Scat_Detector_Mask" in the Browse table) may not be the same as the set of detectors that triggered GBM ("Bcat_Detector_Mask" in the Browse table);
3) background definitions are different for the bcat and scat analysis (see References below).
Finally, for weak events, it is not always possible to perform duration or spectral analyses, and some bursts occur too close in time to South Atlantic Anomaly entries or exits by Fermi with resultant data truncations that prevent background determinations for the duration analysis. There is not an exact one-to-one correspondence between those events for which the duration analysis fails and those which are too weak to have a useful spectral characterization. This means that in the HEASARC Browse table there are a handful of GRBs which have duration parameters but not spectral fit parameters, and vice versa. In these cases, blank entries in the table indicate missing values where an analysis was not possible. Values of 0.0 for the uncertainties on spectral parameters indicate those parameters have been fixed in the fit from which other parameters or quantities in the table were derived. Missing values for model fit parameters indicate that the fit failed to converge for this model. This is true mostly for the more complicated models (SBPL or BAND) when the fits fail to converge for weaker bursts. Bad spectral fits can often result in unphysical flux and fluence values with undefined errors. We include these bad fits but leave the error fields blank when they contain undefined values. The selection criteria used in the first catalog (Goldstein et al. 2011) for the determination of the best-fit spectral model are different from those in the second catalog (Gruber et al. 2014). The results using the two methods on the sample included in Goldstein et al. (2011) are compared in Gruber et al. (2014). The old catalog files can be retrieved using the HEASARC ftp archive tree, under "previous" directories. The values returned by Browse always come from the "current" directories. The chi-squared statistic was not used in the 2nd catalog, either for parameter optimization or model comparison. The chi-squared values are missing for a few GRBs. This is believed to be because of a known software issue and should not be considered indicative of a bad fit.
The variable "scatalog" included in the Browse tables and in the FITS files indicates which catalog a file belongs to, with 2 being the current catalog, and 1 (or absent) the first catalog (preliminary values may appear with value 0).
The main table for each GRB contains an entry for each satellite that reports a detection with either a flux and/or position measurement. Therefore for a given GRB there are multiple records if the GRB was detected by more than one satellite. The associated flux table contains an entry for each flux and fluence values reported in literature for a given energy band. The positional information is reported via different tables each dedicated to a specific region of detection. The region descriptions are the following : circle, annulus, box, dual, annulus intersect, irregular, and intersect.
The associated afterglow table contains position, intensity and redshift measurements taken after the discovery of the GRB. There are several records associated to a given GRB/afterglow since several observatories collected data on that position.
The main table and the associated tables are updated when a new GRB and/or afterglow measurements are reported.
The catalog has been created using information from journal publications, IAU circulars, and GCN notices, and records afterglow measurements for bursts detected after May 1996.
Each record within this catalog is dedicated to a specific measurement of an afterglow made with an observatory. Therefore for a given GRB, there are several entries reporting afterglow measurements from the different observatories.
This catalog is linked to the main GRB catalog and it is updated when a new GRB and/or afterglow measurements are reported.
This table contains the description only for the annulus region type, the other types are stored in separate tables. The annulus region is described by a center given in RA and Dec, the radius of the annulus (corresponding to the center betewen the inner and outer radii) and by the half-width of the annulus.
The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (local_notes). The literature references are provided in the GRBs Catalog main table which is linked to this region table.
This table contains the description only for the box region type, the other types are stored in separate tables. The box region is defined by the corners of the box and a center given in RA and Dec. The number of corners to describe the box is up to six and for each corner the RA and Dec is provided.
In a few cases, Laros et al. (1998) report "hybrid" boxes which are based on either the IPN and the BATSE-only or COMPTEL-only error regions were used. These hybrid boxes are defined by segments of one of the IPN annuli and an area. The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (local_notes).
The literature references are provided in the GRBs Catalog main table which is linked to this region table.
This table contains the description only for the circle region type, the other types are stored in separate tables. The circle region is described by a center given in RA and Dec, and a radius given in degrees.
The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (local_notes).
The literature references are provided in the GRBs Catalog main table which is linked to this region table.
This table contains the description only for the dual region type, the other types are stored in separate tables. The dual region type is for GRBs that had the localization defined by two error circle regions. The dual regions are defined by the centers of the two circle region given in RA and Dec and their radii given in degrees.
The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (local_notes).
The literature references are provided in the GRBs Catalog main table which is linked to this region table.
If an observatory measured flux and fluence in different energy bands, the table contains separate record for each energy band. The table therefore can contain several records associated to a given GRB depending on the number of observatories providing measurements and on the different energy bands.
The measurements are reported as found in literature with the units used by the original authors and not always flux and fluence (and their errors) are both present. The literature references are provided in the GRBs Catalog main table which is linked to this flux table.
This table contains the description only for the region type intersect, the other types are stored in separate tables.
This localization region consists of a box derived from the intersection of the IPN annulus with the region determined by a different observatory. The table lists the corners of the final box intersection and the parameters that defined the IPN annulus (center, radius and half-width). The region of the other observatories that intersect with the IPN annulus is listed with the record for this GRB associated with the other observatory.
The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (localization_notes).
The literature references are provided in the GRBs Catalog main table which is linked to this region table.
This table contains the description only for the annuli intersect region type, the other types are stored in separate tables. This localization region consists of in the intersection up to three annuli. Each annulus is described by a center given in RA and Dec, the radius of the annulus and by the half- width of the annulus.
The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (local_notes).
The literature references are provided in the GRBs Catalog main table which is linked to this region table.
This table contains the description only for the irregular region type, the other types are stored in separate tables. The 'irregual' region are from the Kippen et al. (1998).
This localization region consist of a short thin arc segment derived from a COMPTEL localization combined with an IPN localization where the most likely position corresponds to the maximum obtained from the integral distribution. The COMPTEL localization consists of a circle error region centered at the most likely position within that region.
The measurements are reported as found in literature and any differences or remarks are included in one of the table parameter (local_notes).
The literature references are provided in the GRBs Catalog main table which is linked to this region table.
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 table lists the properties of 388 GRB candidates detected from Oct 27, 2002 to Jan 15, 2005 with the Anti-Coincidence Shield (ACS) of SPI. It has numerous events with missing entries, notice. For all GRBs which were confirmed by other instruments but were detected by SPI-ACS below the sample selection threshold, only the time, date, significance and common instruments are listed. Furthermore, the variability measure was obtained only for long-duration events which had sufficiently large signal-to-noise ratios.
The primary disadvantage of the IPN method, however, is the 1-day to 1.5-day delay in the acquisition of data from all the spacecraft in the network. Interplanetary GRB networks have been in existence since 1977, contributing to the studies of various astrophysical gamma-ray transients, most notably GRBs and SGRs (soft gamma repeaters).
The IPN3 began operations in 1990, with the launch of the Ulysses spacecraft. It was joined by the Compton Gamma Ray Observatory in 1991. Pioneer Venus Orbiter, Mars Observer, and the Italian X-ray astronomy satellite BeppoSAX were part of the network while they were operating. Twenty-six experiments or missions have joined the network so far. Today, the main spacecrafts contributing their data are Konus-WIND, Mars Odyssey, INTEGRAL, RHESSI, Swift, Agile, BepiColombo, and Fermi. XMM-Newton and MAXI are kept to record the cosmic ray and SGR but not used for triangulation because of the different energy range.
The IPNGRB database table is derived from a list provided by Kevin Hurley <khurley@ssl.berkeley.edu>, based on the IPN3. The initial list also includes particles and solar events as well as unconfirmed SGRs and GRBs. The IPNGRB database includes only the observations of confirmed cosmic gamma-ray bursts and SGR since the launch of the Ulysses spacecraft. It is updated every time a new list is provided to the HEASARC.
The authors used the RHESSI GRB Catalog (Wigger et al., 2008, http://grb.web.psi.ch/) and the Cosmic Burst List (Hurley, 2008, http://www.ssl.berkeley.edu/ipn3/masterli.html) to detect 487 GRBs in the RHESSI data over the time period between 2002 February 14 and 2008 April 25. For a deeper analysis, they chose a subset of 427 GRBs with data with a signal-to-noise ratio higher than 6. This table contains this subset.
The compiled sample consists of 304 GRBs observed with radio telescopes between 1997 January and 2011 January, along with the 2011 April 28 Fermi burst, GRB 110428A. The sample consists of a total of 2,995 flux density measurements taken in the frequency range from 0.6 to 660 GHz and spanning a time range from 0.026 to 1,339 days. Most of the afterglows (270 in total) in this sample were observed as part of VLA radio afterglow programs, whereas 15 bursts were observed by the Expanded VLA (EVLA), and 19 southern bursts with the Australia Telescope Compact Array (ATCA). This catalog describes the radio, optical and X-ray afterglow detections (see Section 2.2 of the reference paper): out of the 304 bursts, 123 bursts were observed in the pre-Swift epoch from 1997 until 2004. The remaining 181 bursts were observed between 2005 and 2011 April (the post-Swift epoch).
Out of the 95 radio-detected afterglows (see Section 2.2 of the reference paper), 63 had radio lightcurves (i.e., three or more detections in a single radio band), whereas 32 bursts had less than three detections. For the GRBs for which the light curves were available, the authors determined the peak flux density and the time of the peak in the VLA frequency bands (i.e., 1.4 GHz, 4.9 GHz, 8.5 GHz, 15 GHz, and 22.5 GHz bands) by fitting the data with forward shock formula of the form (Frail 2005, IAU Coll. 192, p. 451) given in equation (1) of the reference paper. This formula may not accurately represent the full complexity of the radio lightcurve evolution. However, it is good enough to determine the approximate values for the peak flux density Fm and the time of the peak tm. See the discussion in Section 3.5 of the reference paper for more details and some caveats. For the remaining bursts, the flux density values were taken directly from the data, and hence do not have the best-fit errors for the peak flux, peak time and rest-frame peak time parameters Fm, tm and tm/(1+z), respectively.
The GRS was designed for investigation of the gamma-ray spectrum of solar flares (Forrest, D.J. et al. 1980, Sol. Phys., 65, 15). The main detector was an array of seven gain-controlled 7.6 cm diameter X 7.6 cm thick NaI(Tl) detectors. A complete spectrum was obtained every 16.38 seconds in the energy range 0.3-9 MeV. The number of counts in three energy windows covering the 4.2-6.4 MeV range was read out every 2.048 seconds. In addition, the number of counts in an approximately 50 keV wide window near 300 keV was read out every 64 milliseconds. The spectrometer was shielded by a 2.5 cm thick CsI(Na) annulus and a 25 cm diameter X 7.6 cm thick CsI(Na) back detector. The shield elements defined a field of view of approximately 135 degrees (FWHM) in the solar direction. The CsI back detector and the seven NaI detectors together provided a high-energy spectrometer with approximately 100 cm^2 effective area and four energy channels from 10 to 100 MeV. The number of counts in those high-energy channels was read out every 2.048 seconds. The experiment was complemented by two 8 cm^2 X 0.6 cm thick NaI(Tl) detectors which measured the X-ray portion of the spectrum every 1.024 seconds in the range from 13 keV to 182 keV.
The current database contains all bursts observed by Swift from the beginning of the mission, 20 Nov 2004 up to 31 Dec 2012. The data products are available for Bursts detected after 15 Feb 2005.