# Shadow of a rotating squashed Kaluza-Klein black hole

## TL;DR

This paper investigates the unique shadow properties of rotating squashed Kaluza-Klein black holes, revealing how extra dimensions and rotation influence shadow shape and size, with implications for astrophysical observations.

## Contribution

It introduces the study of black hole shadows in the context of squashed Kaluza-Klein black holes, highlighting effects of extra dimensions and rotation not seen in standard black holes.

## Key findings

- Shadow shape can be a perfect disk or absent depending on parameters.
- Shadow radius decreases with increasing black hole rotation.
- Shadow size is affected by extra dimension parameters.

## Abstract

We study the shadow of a rotating squashed Kaluza-Klein (KK) black hole and the shadow is found to possess distinct properties from those of usual rotating black holes. It is shown that the shadow for a rotating squashed KK black hole is heavily influenced by the specific angular momentum of photon from the fifth dimension. Especially, as the parameters lie in a certain special range, there is no any shadow for a black hole, which does not emerge for the usual black holes. In the case where the black hole shadow exists, the shadow shape is a perfect black disk and its radius decreases with the rotation parameter of the black hole. Moreover, the change of the shadow radius with extra dimension parameter also depends on the rotation parameter of black hole. Finally, with the latest observation data, we estimate the angular radius of the shadow for the supermassive black hole Sgr $A^{*}$ at the centre of the Milky Way galaxy and the supermassive black hole in $M87$.