Appearance of Keplerian discs orbiting on both sides of reflection-symmetric wormholes

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 reflection-symmetric Simpson-Visser wormholes, in dependence on their parameter and inclination angle of distant observers. We demonstrate significant differences in appearance of the discs on the our side and the other side of the Simpson-Visser wormholes. Large part of the other-side disc is always in 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.