Observing the shadow of Einstein-Maxwell-Dilaton-Axion black hole

Understand

In this paper, the shadows cast by Einstein-Maxwell-Dilaton-Axion black hole and naked singularity are studied.

• The shadow of a rotating black hole is found to be a dark zone covered by a deformed circle.
• For a fixed value of the spin $a$, the size of the shadow decreases with the dilaton parameter $b$.
• The distortion of the shadow monotonically increases with $b$ and takes its maximal when the black hole approaches to the extremal case.