Appearance of Keplerian discs orbiting on both sides of a reflection-symmetric wormhole

TL;DR

This paper analyzes the optical appearance and spectral lines of Keplerian discs around a reflection-symmetric wormhole, revealing observable differences that could distinguish such wormholes from black holes.

Contribution

It provides the first detailed modeling of the optical appearance and spectral features of discs around a reflection-symmetric wormhole, highlighting observable signatures.

Findings

Discs on opposite sides of the wormhole show significant visual differences.

The spectral lines depend differently on spacetime parameters and inclination angle.

Distinct spectral line shapes can help identify reflection-symmetric wormholes observationally.

Abstract

We construct optical appearance and profiled spectral lines of Keplerian discs with inner edge at the innermost circular geodesic located on both sides of the reflection-symmetric Simpson-Visser wormhole, in dependence on its parameter and inclination angle of a distant observer. We demonstrate significant differences in appearance of the discs on the our side and the other side of the wormhole. Large part of the other-side disc is always in the dark region of the image of the disc orbiting on the our side, enabling thus a simple distinguishing in observations. The profiled spectral lines generated by the disc on the other side (our side) demonstrate strong (weak) dependence on the spacetime parameter, and weak (strong) dependence on the inclination angle; they have also different shape, giving thus other clues to clearly distinguish in observations reflection-symmetric wormholes as alternatives to black holes.