What does a binary black hole merger look like?

TL;DR

This paper introduces a method to simulate strong gravitational lensing effects caused by black holes and black hole binaries, revealing complex and self-similar image distortions on small scales.

Contribution

It presents a novel technique for calculating gravitational lensing in various black hole spacetimes, including numerical simulations of binary systems, with detailed visualizations.

Findings

Lensing from inspiraling binaries resembles single black holes on large scales.

Small-scale images show complex, self-similar structures.

The method produces both illustrative and realistic star field images.

Abstract

We present a method of calculating the strong-field gravitational lensing caused by many analytic and numerical spacetimes. We use this procedure to calculate the distortion caused by isolated black holes and by numerically evolved black hole binaries. We produce both demonstrative images illustrating details of the spatial distortion and realistic images of collections of stars taking both lensing amplification and redshift into account. On large scales the lensing from inspiraling binaries resembles that of single black holes, but on small scales the resulting images show complex and in some cases self-similar structure across different angular scales.