Thin accretion disk in the Simpson-Visser black-bounce and wormhole spacetimes.

We compare the optical appearance of a thin accretion disk in the Simpson-Visser spacetime to the Schwarzschild black hole case in this paper. We calculate and illustrate the redshift and observed flux distributions as viewed by distant observers at various inclination angles. Simpson-Visser family of metrics creates Novikov-Thorne (NT) accretion disks images that nearly look like a Schwarzschild black hole's NT accretion disk. We have studied also the embedding diagram, the electromagnetic properties of the accretion disk such as the temperature and the radiation flux of the energy by the accretion disk and the accretion efficiency. Compared to the Schwarzschild black hole, we find that the temperature, radiation flux of the energy, and the luminosity of the accretion disk increase by increasing the regularization parameter l. We conclude that, based on astrophysical observational signatures in the properties of the electromagnetic spectrum, we can distinguish the wormhole geometries from the regular black holes (black-bounce) and the Schwarzschild black hole. [ABSTRACT FROM AUTHOR]