Adding Gamma-ray Polarimetry to the Multi-Messenger Era by Merlin Kole et al. on Thursday 24 November

The last decade has seen the emergence of two new fields within astrophysics:

gamma ray polarimetry and GW astronomy. The former, which aims to measure the

polarization of gamma rays in the energy range of 10s to 100s of keV, from

astrophysical sources, saw the launch of the first dedicated polarimeters such

as GAP and POLAR. On the other hand, GW astronomy started with the detection of

the first black hole mergers by LIGO in 2015, followed by the first multi

messenger detection in 2017. While the potential of the two individual fields

has been discussed in detail in the literature, the potential for joint

observations has thus far been ignored. In this article, we aim to define how

GW observations can best contribute to gamma ray polarimetry and study the

scientific potential of joint analyses. In addition we aim to provide

predictions on feasibility of such joint measurements in the near future. We

study which GW observables can be combined with measurements from gamma ray

polarimetry to improve the discriminating power regarding GRB emission models.

We then provide forecasts for the joint detection capabilities of current and

future GW detectors and polarimeters. Our results show that by adding GW data

to polarimetry, a single precise joint detection would allow to rule out the

majority of emission models. We show that in the coming years joint detections

between GW and gamma ray polarimeters might already be possible. Although these

would allow to constrain part of the model space, the probability of highly

constraining joint detections will remain small in the near future. However,

the scientific merit held by even a single such measurement makes it important

to pursue such an endeavour. Furthermore, we show that using the next

generation of GW detectors, such as the Einstein Telescope, joint detections

for which GW data can better complement the polarization data become possible.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.12403v1