# A DISTINCT PEAK-FLUX DISTRIBUTION OF THE THIRD CLASS OF GAMMA-RAY BURSTS: A POSSIBLE SIGNATURE OF X-RAY FLASHES?

@article{Veres2010ADP,
title={A DISTINCT PEAK-FLUX DISTRIBUTION OF THE THIRD CLASS OF GAMMA-RAY BURSTS: A POSSIBLE SIGNATURE OF X-RAY FLASHES?},
author={P{\'e}ter Veres and Zs. Bagoly and Istv'an Horv'ath and A. M'esz'aros and Lajos G. Bal'azs},
journal={The Astrophysical Journal},
year={2010},
volume={725},
pages={1955 - 1964}
}
• Published 11 October 2010
• Physics
• The Astrophysical Journal
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 intermediate duration and softest spectrum. We are looking for physical properties which discriminate the intermediate duration bursts from the other two classes. We use maximum likelihood fits to establish group memberships in the duration–hardness plane. To confirm these results we also use k-means…

## Figures and Tables from this paper

### 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,

### ON THE PROPERTIES OF SPECTRAL LAGS AND PEAK-COUNT RATES OF RHESSI GAMMA-RAY BURSTS

• Physics
Gamma-ray Bursts: 15 Years of GRB Afterglows
• 2020
A sample of 427 gamma-ray bursts (GRBs) was observed by the RHESSI satellite in Feb. 2002 - Apr. 2008. We calculated spectral lags and peak-count rates for the first time and constructed a new

### Gamma-ray bursts: A brief survey of the diversity

• Physics
Proceedings of the International Astronomical Union
• 2018
Abstract The separation of the gamma-ray bursts (GRBs) into short/hard and long/soft subclasses, respectively, is well supported both theoretically and observationally. The long ones are coupled to

### On the connection of gamma-ray bursts and X-ray flashes in the BATSE and RHESSI databases

• Physics
• 2016
Classification of gamma-ray bursts (GRBs) into groups has been intensively studied by various statistical tests in previous years. It has been suggested that there was a distinct group of GRBs,

### A redshift-observation time relation for gamma-ray bursts: evidence of a distinct subluminous population

• Physics
• 2013
We show that the redshift and peak flux distributions of gamma-ray bursts (GRBs) have an observation time dependence that can be used to discriminate between different burst populations. We

### Testing the Isotropic Universe Using the Gamma-Ray Burst Data of Fermi/GBM

• Physics
• 2017
The sky distribution of gamma-ray bursts (GRBs) has been intensively studied by various groups for more than two decades. Most of these studies test the isotropy of GRBs based on their sky number

### GEMINI SPECTROSCOPY OF THE SHORT-HARD GAMMA-RAY BURST GRB 130603B AFTERGLOW AND HOST GALAXY

• Physics
• 2013
We present early optical photometry and spectroscopy of the afterglow and host galaxy of the bright short-duration gamma-ray burst GRB 130603B discovered by the Swift satellite. Using our Target of

### How does the shape of gamma-ray bursts’ pulses affect the duration distribution?

• M. Tarnopolski
• Physics
Monthly Notices of the Royal Astronomical Society
• 2021
Gamma-ray bursts (GRBs) come in two types, short and long. The distribution of logarithmic durations of long GRBs is asymmetric rather than Gaussian. Such an asymmetry, when modelled with a mixture

### THE THIRD FERMI GBM GAMMA-RAY BURST CATALOG: THE FIRST SIX YEARS

• Physics
• 2016
Since its launch in 2008, the Fermi Gamma-ray Burst Monitor (GBM) has triggered and located on average approximately two γ-ray bursts (GRBs) every three days. Here, we present the third of a series

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

• Mathematics
• 2016
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

## References

SHOWING 1-10 OF 42 REFERENCES

### Classification of Swift's gamma-ray bursts

• Physics
• 2008
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

### Three Types of Gamma-Ray Bursts

• Physics
• 1998
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

### Duration distributions for different softness groups of gamma-ray bursts

• 2010
Gamma-ray bursts (GRBs) are divided into two classes according to their durations. We investigate if the softness of bursts plays a role in the conventional classification of the objects. We employ

### Frequency of fast, narrow γ-ray bursts

• Physics
Nature
• 1984
Early studies of the time histories of the γ-ray burst events reported by the Vela satellites led to the suggestion that very brief, ∼ 0.1 s, bursts formed a class distinct from the longer, highly

### A NEW CLASSIFICATION METHOD FOR GAMMA-RAY BURSTS

• Physics
• 2010
Recent Swift observations suggest that the traditional long versus short gamma-ray burst (GRB) classification scheme does not always associate GRBs to the two physically motivated model types, i.e.,

### BATSE observations of gamma-ray burst spectra. I: Spectral diversity

• Physics
• 1993
We studied the time-averaged gamma-ray burst spectra accumulated by the spectroscopy detectors of the Burst and Transient Source Experiment. The spectra are described well at low energy by a

### Search for Gamma-Ray Burst Classes with the RHESSI Satellite

• Mathematics
• 2009
A sample of 427 gamma-ray bursts (GRBs), measured by the RHESSI satellite, is studied statistically with respect to duration and hardness ratio. Standard statistical tests are used, such as $\chi^2$,

### How Sample Completeness Affects Gamma-Ray Burst Classification

• Physics
• 2003
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,

### Identification of two classes of gamma-ray bursts

• Physics
• 1993
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

### The Hardness-Duration Diagram of Gamma-Ray Bursts

• Physics
• 1996
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