On the detectability of dual jets from binary black holes

TL;DR

This paper investigates the electromagnetic emissions from merging supermassive black holes, finding that dual jets are present but weak compared to other emissions, which impacts their detectability.

Contribution

The study provides a detailed analysis showing dual jets are energetically subdominant, refining previous models and improving understanding of electromagnetic signals from black hole mergers.

Findings

Dual jets are present but energetically weak.

Electromagnetic emission is mainly quadrupolar and non-collimated.

Detection of dual jets from mergers is challenging.

Abstract

We revisit the suggestion that dual jets can be produced during the inspiral and merger of supermassive black holes when these are immersed in a force-free plasma threaded by a uniform magnetic field. By performing independent calculations and by computing the electromagnetic emission in a way which is consistent with estimates using the Poynting flux, we show that a dual-jet structure is present but energetically subdominant with respect to a non-collimated and predominantly quadrupolar emission, which is similar to the one computed when the binary is in electrovacuum. While our findings set serious restrictions on the detectability of dual jets from coalescing binaries, they also increase the chances of detecting an EM counterpart from these systems.