THE SECOND FERMI GBM GAMMA-RAY BURST CATALOG: THE FIRST FOUR YEARS

Abstract

This is the second of a series of catalogs of gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM). It extends the first two-year catalog by two more years, resulting in an overall list of 953 GBM triggered GRBs. The intention of the GBM GRB catalog is to provide information to the community on the most important observables of the GBM detected GRBs. For each GRB the location and main characteristics of the prompt emission, the duration, peak flux and fluence are derived. The latter two quantities are calculated for the 50-300 keV energy band, where the maximum energy release of GRBs in the instrument reference system is observed and also for a broader energy band from 10-1000 keV, exploiting the full energy range of GBMs low-energy detectors. Furthermore, information is given on the settings and modifications of the triggering criteria and exceptional operational conditions during years three and four in the mission. This second catalog is an official product of the Fermi GBM science team, and the data files containing the complete results are available from the

The Third Swift Burst Alert Telescope Gamma-Ray Burst Catalog

“…23 Similarly, the start and end time of T 50 is defined as the times when the accumulated light curve reaches 25% and 75%. These definitions for T 90 and T 50 are commonly adopted for quantifying burst durations by other teams, including BATSE, BeppoSAX, and Fermi (Koshut et al 1996;Paciesas et al 1999;Frontera et al 2009;von Kienlin et al 2014). In this paper, we follow the convention and use the T 90 =2 s as the separation between the long and short GRBs categories (Kouveliotou et al 1993).…”

“…For the BAT GRBs, only bursts with successfully determined are included in the plot. T 90 for Fermi/GBM bursts are obtained from the Fermi GBM burst catalog (Gruber et al 2014;von Kienlin et al 2014). T 90 for CGRO/BATSE bursts are from The Fourth Gamma-ray Bursts Catalog (Paciesas et al 1999).…”

“…We use these trigger numbers in the fake TDRSS Figure 12. E peak distributions for GRBs detected by Fermi (Gruber et al 2014;von Kienlin et al 2014) and BATSE (Goldstein et al 2013). Distributions using the upper and lower bounds of the E peak uncertainty range are also plotted for comparison.…”

“…The middle and bottom panels of Figure 7 shows the T 90 distributions for GRBs detected by Fermi and BATSE for comparison. T 90 of the Fermi GRBs are obtained from the Fermi GBM burst catalog 30 (Gruber et al 2014;von Kienlin et al 2014), and T 90 of the BATSE GRBs are from The Fourth Gamma-ray Bursts Catalog (Paciesas et al 1999). Compared to the short GRB fraction in the Swift/BAT GRB sample (∼9%), the fractions of short bursts are larger in both the Fermi GRB sample (∼17%) and the BATSE sample (∼26%).…”

Analysis ofFermigamma-ray burst duration distribution

“…In the others, a three-Gaussian distribution was found to follow the histogram better than a two-Gaussian, but those fits yielded only two peaks, so although statistical analyses support the presence of a third class, its existence is still elusive and may be due to selection and instrument effects, or might be described by a distribution that is not necessarily a mixture of Gaussians. The latest release is due to Fermi GBM observations (Gruber et al 2014;von Kienlin et al 2014) and consists of 1568 GRBs 1 with calculated T 90 . This sample, to the best of the author's knowledge, has not yet been investigated for the presence of an intermediate class; only Horváth et al (2012) and Qin et al (2013) conducted research on a subsample consisting of 425 bursts from the first release of the catalog.…”