Comparing short gamma-ray burst jet structure models

Hayes, F. , Heng, I. S. , Veitch, J. and Williams, D. (2020) Comparing short gamma-ray burst jet structure models. Astrophysical Journal, 891(2), 124. (doi: 10.3847/1538-4357/ab72fc)

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Abstract

A structured gamma-ray burst (GRB) jet could explain the dimness of the prompt emission observed from GRB 170817A, but the exact form of this structure is still ambiguous. However, with the promise of future joint gravitational wave (GW) and GRB observations, we shall be able to examine populations of binary neutron star (BNS) mergers rather than on a case-by-case basis. We present an analysis that considers GW triggered BNS events both with and without short GRB counterparts assuming that events without a counterpart were observed off-axis. This allows for Bayes factors to be calculated to compare different jet structure models. We perform model comparison between a Gaussian and power-law apparent jet structure on simulated data to demonstrate that the correct model can be distinguished with a log Bayes factor of >5 after fewer than 100 events. Constraints on the apparent structure jet model parameters are also made. After 25(100) events the angular width of the core of a power-law jet structure can be constrained within a 90% credible interval of width ~9.1(4.4)°, and the outer beaming angle to be within ~19.9(8.5)°. Similarly, we show the width of a Gaussian jet structure to be constrained to ~2.8(1.6)°.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Heng, Professor Ik Siong and Williams, Dr Daniel and Hayes, Dr Fergus and Veitch, Dr John
Authors: Hayes, F., Heng, I. S., Veitch, J., and Williams, D.
College/School:College of Science and Engineering > School of Physics and Astronomy
Research Centre:College of Science and Engineering > School of Physics and Astronomy > Institute for Gravitational Research
Journal Name:Astrophysical Journal
Publisher:IOP Publishing
ISSN:0004-637X
ISSN (Online):1538-4357
Copyright Holders:Copyright © 2020 American Astronomical Society
First Published:First published in Astrophysical Journal 891(2):124
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
172031STFC 2015 DTPMartin HendryScience and Technology Facilities Council (STFC)ST/N504075/1P&S - Physics & Astronomy
173808Investigations in gravitational radiationSheila RowanScience and Technology Facilities Council (STFC)ST/N005422/1P&S - Physics & Astronomy
173808Investigations in gravitational radiationSheila RowanScience and Technology Facilities Council (STFC)ST/N005422/1P&S - Physics & Astronomy
301152Surveying black holes and neutron stars with gravitational wavesJohn VeitchScience and Technology Facilities Council (STFC)ST/K005014/2P&S - Physics & Astronomy