Fermi GBM signal contemporaneous with GW150914 - an unlikely association

TL;DR

This paper critically assesses the potential association between a Fermi GBM signal and GW150914, concluding that the physical and statistical evidence strongly suggests they are unrelated events.

Contribution

It provides a detailed analysis showing the implausibility of the electromagnetic signal being associated with the black hole merger based on physical constraints and probability.

Findings

Physical constraints are highly implausible for association.

The probability of coincidence is 0.22 percent.

The electromagnetic signal is likely unrelated to GW150914.

Abstract

We argue that the physical constraints required by the association of the Fermi GBM signal contemporaneous with GW150914 - radiative power of $10^{49} $ erg s$^{-1}$, and corresponding magnetic fields on the black hole of the order of $10^{12}$ Gauss - are astrophysical highly implausible. Combined with the relatively high random probability of coincidence of 0.22 percents, we conclude that the electromagnetic signal is likely unrelated to the BH merger.