# Electromagnetic Radiation Accompanying Gravitational Waves from Black Hole Binaries

## TL;DR

This paper investigates how gravitational waves from black hole mergers can generate electromagnetic signals in plasma environments, especially considering realistic low-frequency conditions, potentially explaining observed electromagnetic counterparts.

## Contribution

It provides a detailed analysis of graviton-to-photon conversion in plasma at frequencies below the plasma frequency, extending previous models to more realistic astrophysical scenarios.

## Key findings

- Electromagnetic radiation can be generated by gravitational waves in plasma despite low frequencies.
- Plasma heating may produce detectable electromagnetic bursts with higher frequencies.
- The mechanism could explain electromagnetic counterparts of black hole merger events.

## Abstract

The transformation of powerful gravitational waves, created by the coalescence of massive black hole binaries, into electromagnetic radiation in external magnetic fields is revisited. In contrast to the previous calculations of the similar effect, we study the realistic case of the gravitational radiation frequency below the plasma frequency of the surrounding medium. The gravitational waves propagating in the plasma constantly create electromagnetic radiation dragging it with them, despite the low frequency. The plasma heating by the unattenuated electromagnetic wave may be significant in a hot rarefied plasma with strong magnetic field and can lead to a noticeable burst of electromagnetic radiation with higher frequency. The graviton-to-photon conversion effect in plasma is discussed in the context of possible electromagnetic counterparts of GW150914 and GW170104.