February 2024 | Ivo Sengo, Pedro V.P. Cunha, Carlos A. R. Herdeiro, Eugen Radu
This paper investigates the lensing images of dynamically robust rotating (mini-)Proca stars surrounded by thin accretion disks, aiming to show how these objects can mimic the appearance of black holes (BHs). The study focuses on the geodesic structure of these stars and how their lensing images resemble those of BHs, particularly when considering a GRMHD-motivated emission cutoff. Unlike non-rotating cases, these similarities persist even for equatorial observations, suggesting that horizonless compact objects without light rings could mimic BH features.
The research explores the structure of Proca stars, their accretion disk profiles, and the resulting gravitational lensing effects. The study considers different cases of Proca star solutions, each with distinct timelike circular orbit (TCO) structures. The analysis reveals that rotating Proca stars can produce lensing images that closely resemble those of BHs, especially when the accretion disk has a cutoff in its intensity profile. This cutoff can be associated with the existence of an Innermost Stable Circular Orbit (ISCO) or other geodesic structures.
The paper also discusses the inclusion of redshift effects in the lensing images, showing how the observed frequency of photons emitted from the disk differs from their local frequency due to gravitational redshift. The results demonstrate that Proca stars, when illuminated by geometrically thin and optically thick accretion disks, can mimic the visual appearance of BHs, even under edge-on observation scenarios. This finding supports the idea that dynamically robust, horizonless compact objects could serve as viable alternatives to BHs in astrophysical contexts. The study highlights the importance of considering the complex geodesic structures of these objects in understanding their potential to mimic BH features.This paper investigates the lensing images of dynamically robust rotating (mini-)Proca stars surrounded by thin accretion disks, aiming to show how these objects can mimic the appearance of black holes (BHs). The study focuses on the geodesic structure of these stars and how their lensing images resemble those of BHs, particularly when considering a GRMHD-motivated emission cutoff. Unlike non-rotating cases, these similarities persist even for equatorial observations, suggesting that horizonless compact objects without light rings could mimic BH features.
The research explores the structure of Proca stars, their accretion disk profiles, and the resulting gravitational lensing effects. The study considers different cases of Proca star solutions, each with distinct timelike circular orbit (TCO) structures. The analysis reveals that rotating Proca stars can produce lensing images that closely resemble those of BHs, especially when the accretion disk has a cutoff in its intensity profile. This cutoff can be associated with the existence of an Innermost Stable Circular Orbit (ISCO) or other geodesic structures.
The paper also discusses the inclusion of redshift effects in the lensing images, showing how the observed frequency of photons emitted from the disk differs from their local frequency due to gravitational redshift. The results demonstrate that Proca stars, when illuminated by geometrically thin and optically thick accretion disks, can mimic the visual appearance of BHs, even under edge-on observation scenarios. This finding supports the idea that dynamically robust, horizonless compact objects could serve as viable alternatives to BHs in astrophysical contexts. The study highlights the importance of considering the complex geodesic structures of these objects in understanding their potential to mimic BH features.