English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The optical characteristics of three types of black holes (BHs) surrounded bya thin accretion disk are discussed, namely the Schwarzschild BH, Bardeen BH,and Hayward BH. We calculate the deflection angle of light as it traverses thevicinity of each BH using numerical integration and semi-analytical methods,revealing that both approaches can effectively elucidate the deflection oflight around the BH. We investigate the optical appearance of the accretiondisk and its corresponding observational images at various viewing angles,discovering that the luminosity in the region near the BH on the inner side ofthe accretion disk is higher than that on the outer side owing to highermaterial density in closer proximity to the BH. We observe a significantaccumulation of brightness on the left side of the accretion disk, attributedto the motion of matter and geometric effects. Our findings emphasize thesignificant influence of the observation inclination angle on the observedoutcomes. An increase in the observation inclination angle results in theseparation of higher-order images. With the improvement in EHT observationaccuracy, we believe that the feature of a minimal distance between theinnermost region of the direct image of the Hayward BH and the outermost regionof the secondary image can be used as an indicator for identifying Hayward BHs.

Unveiling the unconventional optical signatures of regular black holes within accretion disk