Modifications to the signal from a gravitational wave event due to a surrounding shell of matter

TL;DR

This paper investigates how surrounding matter shells can modify gravitational wave signals, clarifying that such shells cannot produce echoes but can cause small signal alterations in various astrophysical events.

Contribution

It applies theoretical results to astrophysical scenarios, demonstrating the limited impact of matter shells on GW echoes and quantifying possible signal modifications.

Findings

GW echoes are not caused by matter shells.

Matter shells can cause a few percent modifications to GW signals.

Scenarios include black hole mergers, neutron star mergers, and supernovae.

Abstract

In previous work, we established theoretical results concerning the effect of matter shells surrounding a gravitational wave (GW) source, and we now apply these results to astrophysical scenarios. Firstly, it is shown that GW echoes that are claimed to be present in LIGO data of certain events, could not have been caused by a matter shell. However, it is also shown that there are scenarios in which matter shells could make modifications of order a few percent to a GW signal; these scenarios include binary black hole mergers, binary neutron star mergers, and core collapse supernovae.