Campus Units

Statistics

Document Type

Article

Publication Version

Published Version

Publication Date

12-2018

Journal or Book Title

Monthly Notices of the Royal Astronomical Society

Volume

481

Issue

3

First Page

3196

Last Page

3209

DOI

10.1093/mnras/sty1940

Abstract

Determining the kinds of gamma-ray bursts (GRBs) has been of interest to astronomers for many years. We analysed 1599 GRBs from the Burst and Transient Source Experiment (BATSE) 4Br catalogue using t-mixture-model-based clustering on all nine observed parameters (T50, T90, F1, F2, F3, F4, P64, P256, and P1024) and found evidence of five types of GRBs. Our results further refine our earlier findings by providing groups that are more distinct. Using the classification scheme of past authors that employed duration, total fluence (Ft = F1 + F2 + F3 + F4), and spectrum [using Hardness Ratio H321 = F3/(F1 + F2)], our five groups are classified as long-intermediate–intermediate, short-faint-intermediate, short-faint-soft, long-bright-hard, and long-intermediate-hard. We also classify 374 GRBs in the BATSE catalogue that have incomplete information in some of the observed variables (mainly the four time integrated fluences F1, F2, F3, and F4) to the five groups obtained, using the 1599 GRBs having complete information in all the observed variables. Our classification scheme puts 138 GRBs in the first group, 52 GRBs in the second group, 33 GRBs in the third group, 127 GRBs in the fourth group, and 24 GRBs in the fifth group.

Comments

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Copyright Owner

The Authors

Language

en

File Format

application/pdf

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