Constraints On Short, Hard Gamma-Ray Burst Beaming Angles From Gravitational Wave Observations

This is the repository for the analysis and the paper related to the method for inferring the GRB opening angle from the rates of gamma ray bursts and neutron star merger events.

The pre-print of the paper describing this work and its results is available on the arXiv as document 1712.02585.

This document also has LIGO-DCC document ID LIGO-P1600102.

Abstract

The first detection of a binary neutron star merger, GW170817, and an associated short gamma-ray burst confirmed that neutron star mergers are responsible for at least some of these bursts. The prompt gamma ray emission from these events is thought to be highly relativistically beamed. We present a method for inferring limits on the extent of this beaming by comparing the number of short gamma-ray bursts observed electromagnetically to the number of neutron star binary mergers detected in gravitational waves. We demonstrate that an observing run comparable to the expected Advanced LIGO 2016--2017 run would be capable of placing limits on the beaming angle of approximately θ ∈ (2.88°,14.15°), given one binary neutron star detection. We anticipate that after a year of observations with Advanced LIGO at design sensitivity in 2020 these constraints would improve to θ ∈ (8.10°,14.95°).

Citing this work

You can cite our arXiv preprint (BibTeX):

@ARTICLE{2017arXiv171202585W,
   author = {{Williams}, D. and {Clark}, J.~A. and {Williamson}, A.~R. and 
 {Heng}, I.~S.},
    title = "{Constraints On Short, Hard Gamma-Ray Burst Beaming Angles From Gravitational Wave Observations}",
    journal = {ArXiv e-prints},
    archivePrefix = "arXiv",
    eprint = {1712.02585},
    primaryClass = "astro-ph.HE",
    keywords = {Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology},
    year = 2017,
    month = dec,
    adsurl = {http://adsabs.harvard.edu/abs/2017arXiv171202585W},
    adsnote = {Provided by the SAO/NASA Astrophysics Data System}
 }

and you can also cite our data release:

@article{williams, daniel_clark, james_williamson, andrew_heng, ik
siong_2017, title={Constraints On Short, Hard Gamma-Ray Burst
Beaming Angles From Gravitational Wave Observations : Supplementary
Material}, DOI={10.5281/zenodo.1066019}, abstractNote={<p>Data and
code to produce the analysis presented in &quot;Constraints On
Short, Hard Gamma-Ray Burst Beaming Angles From<br> Gravitational
Wave Observations&quot;.</p>}, note={This is the version of the
data release which corresponds to v1 of the paper on arXiv. DW is
supported by the Science and Technology Research Council (STFC)
grant ST/N504075/1. JC acknowledges support from NSF awards
PHYS-1505824 and PHYS-1505524SH. ISH is supported by STFC grant
ST/L000946/1. ARW acknowledges support from the Netherlands
Organization for Scientific Research through the NWO TOP Grant
No. 62002444­­-Nissanke. This document has been assigned the
control number LIGO-P1600102 by the LIGO document control centre.},
publisher={Zenodo}, author={Williams, Daniel and Clark, James and
Williamson, Andrew and Heng, Ik Siong}, year={2017}, month={Dec}}

Reproducing our results

This repository contains all of the analysis code required to reproduce the results presented in the paper, however the surface plots require a fairly large amount of time to produce, so for convenience we have provided the data for these in the /data directory. The majority of the analysis is conducted in jupyter format notebooks, and these can be found in the notebooks directory, which has its own README file. To reproduce the analysis for the surface plots see the surface-plot.py script in the scripts directory.

You can install the requirements for this analysis in a virtual environment by first running

pip install -r requirements.txt

inside this directory.