Inclination estimates from off-axis GRB afterglow modelling

Lamb, G. P., Fernández, J. J., Hayes, F. , Kong, A. K. H., Lin, E.-T., Tanvir, N. R., Hendry, M. , Heng, I. S. , Saha, S. and Veitch, J. (2021) Inclination estimates from off-axis GRB afterglow modelling. Universe, 7(9), 329. (doi: 10.3390/universe7090329)

Abstract

For gravitational wave (GW) detected neutron star mergers, one of the leading candidates for electromagnetic (EM) counterparts is the afterglow from an ultra-relativistic jet. Where this afterglow is observed, it will likely be viewed off-axis, such as the afterglow following GW170817/GRB 170817A. The temporal behaviour of an off-axis observed GRB afterglow can be used to reveal the lateral jet structure, and statistical model fits can put constraints on the various model free-parameters. Amongst these parameters is the inclination of the system to the line of sight. Along with the GW detection, the afterglow modelling provides the best constraint on the inclination to the line-of-sight and can improve the estimates of cosmological parameters, for example, the Hubble constant, from GW-EM events. However, modelling of the afterglow depends on the assumed jet structure and—often overlooked—the effects of lateral spreading. Here we show how the inclusion of lateral spreading in the afterglow models can affect the estimated inclination of GW-EM events.

• Item Type: Articles
• Additional Information: G.P.L. is supported by STFC grant ST/S000453/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Heng, Professor Ik Siong and SAHA, SUROJIT and Hayes, Dr Fergus and Veitch, Dr John and Hendry, Professor Martin and Tanvir, Professor Nial

Creator Roles

Hayes, F.: Writing – review and editing, Visualization
Tanvir, N. R.: Writing – review and editing
Hendry, M.: Conceptualization
Heng, I. S.: Writing – review and editing
Saha, S.: Writing – review and editing
Veitch, J.: Writing – review and editing

• Authors: Lamb, G. P., Fernández, J. J., Hayes, F., Kong, A. K. H., Lin, E.-T., Tanvir, N. R., Hendry, M., Heng, I. S., Saha, S., and Veitch, J.
• 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: Universe
• Publisher: MDPI
• ISSN: 2218-1997
• ISSN (Online): 2218-1997
• Published Online: 05 September 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Universe 7(9): 329
• Publisher Policy: Reproduced under a Creative Commons License