Three Types of Gamma-Ray Bursts

  title={Three Types of Gamma-Ray Bursts},
  author={Soma Mukherjee and Eric D. Feigelson and Gutti Jogesh Babu and Fionn Murtagh and Chris Fraley and Adrian E. Raftery},
  journal={The Astrophysical Journal},
  pages={314 - 327}
A multivariate analysis of gamma-ray burst (GRB) bulk properties is presented to discriminate between distinct classes of GRBs. Several variables representing burst duration, fluence, and spectral hardness are considered. Two multivariate clustering procedures are used on a sample of 797 bursts from the Third BATSE Catalog, a nonparametric average linkage hierarchical agglomerative clustering procedure validated with Wilks' Λ* and other multivariate analysis of variance tests and a parametric… 

Figures and Tables from this paper


Gamma-ray bursts (GRBs) are the most luminous events in the universe. Going beyond the short–long classification scheme, we work in the context of three burst populations with the third group of

Analysis of the Duration–Hardness Ratio Plane of Gamma-Ray Bursts Using Skewed Distributions

The two widely accepted classes of gamma-ray bursts (GRBs), short and long, are with confidence ascribed to mergers of compact objects and collapse of massive stars, respectively. A third,

Gaussian-mixture-model-based cluster analysis of gamma-ray bursts in the BATSE catalog

Clustering is an important tool to describe gamma-ray bursts (GRBs). We analyzed the Final BATSE Catalog using Gaussian-mixture-models-based clustering methods for six variables (durations, peak

Classification of Swift's gamma-ray bursts

Context. Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the

Classification of gamma-ray burst durations using robust model-comparison techniques

Gamma-Ray Bursts (GRBs) have been conventionally bifurcated into two distinct categories dubbed “short” and “long”, depending on whether their durations are less than or greater than two seconds

Multivariate Analysis of BATSE Gamma-Ray Burst Properties Using Skewed Distributions

The number of classes of gamma-ray bursts (GRBs), besides the well-established short and long ones, remains a debatable issue. It was already shown, however, that when invoking skewed distributions,

Two dimensional clustering of Gamma-Ray Bursts using durations and hardness

Gamma-Ray Bursts (GRBs) have been traditionally divided into two categories: “short” and “long” with durations less than and greater than two seconds, respectively. However, there is a lot of

Analysis of gamma-ray burst duration distribution using mixtures of skewed distributions

Two classes of GRBs have been confidently identified thus far and are prescribed to different physical scenarios -- NS-NS or NS-BH mergers, and collapse of massive stars, for short and long GRBs,

How Sample Completeness Affects Gamma-Ray Burst Classification

Unsupervised pattern-recognition algorithms support the existence of three gamma-ray burst classes: class 1 (long, large-fluence bursts of intermediate spectral hardness), class 2 (short,

The duration distribution of Swift Gamma-Ray Bursts

Decades ago two classes of gamma-ray bursts were identified and delineated as having durations shorter and longer than about 2 s. Subsequently indications also supported the existence of a third



Spectral evolution of a subclass of gamma-ray bursts observed by batse

Among the gamma-ray bursts (GRBs) observed by the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma Ray Observatory we define a subclass of bursts based on similar morphology:

The continuum spectral characteristics of gamma-ray bursts observed by BATSE

Distributions of the continuum spectral characteristics of 260 bursts in the first Burst and Transient Source Experiment (BATSE) catalog are presented. The data are derived from flux ratios

The Third BATSE Gamma-Ray Burst Catalog

The Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) has triggered on 1122 cosmic gamma-ray bursts between 1991 April 19 and 1994 September 19. These events

Identification of two classes of gamma-ray bursts

We have studied the duration distribution of the gamma-ray bursts of the first BATSE catalog. We find a bimodality in the distribution, which separates GRBs into two classes: short events (less than

Evidence for two distinct morphological classes of gamma-ray bursts from their short time scale variability

We have analyzed the 241 bursts for which peak counts (C)max exist in the publicly available Burst and Transient Source Experiment (BATSE) catalog. Introducing peak counts in 1024 ms as a measure of

Evidence for the Galactic Origin of Gamma-Ray Bursts

We propose a new criterion to divide the classical gamma-ray bursts into two classes on the basis of their distribution in the duration-hardness plane. We study the two proposed classes separately,

The Identification of Two Different Spectral Types of Pulses in Gamma-Ray Bursts

It is shown in this study that two different types of spectral emission are generally produced in gamma-ray bursts. A subset of bursts is identified that exhibits a marked lack of fluence above 300

The Hardness-Duration Diagram of Gamma-Ray Bursts

The hardness-duration diagram for gamma-ray bursts still contains undiscovered important information about the intrinsic properties of these phenomena. We analyze these diagrams for the PHEBUS and

The Long and the Short of Gamma-Ray Bursts

We report evidence from the Third BATSE Gamma-Ray Burst Catalog that long (T90 > 10 s) and short (T90 < 10 s) gamma-ray bursts (GRBs) represent distinct source populations. Their spatial

Duration distributions of bright and dim BATSE gamma-ray bursts

We have measured the T(sub 90) and T(sub 50) durations of bright and dim gamma-ray bursts detected by the Compton Gamma-Ray Observatory's (CGRO) Burst and Transient Source Experiment (BASTE). The