  The $\gamma$-metric is a static, axially-symmetric singular solution of the
vacuum Einstein's equations without an event horizon. This is a two-parameter
family of solutions, generic values of one of which (called $\gamma$) measure
the deviation from spherical symmetry. Here, we first study the shadow cast by
this geometry, in order to constrain the $\gamma$-metric from observations. We
find that for $\gamma < 1/2$, there are, in principle, no shadows cast. On the
other hand, shadows cast for all values of $\gamma \geq 1/2$ are consistent
with observations of M$87^*$ by the Event Horizon Telescope. We also study
images of thin accretion disks in the $\gamma$-metric background. In situations
where the $\gamma$-metric possesses light rings, these qualitatively mimic
Schwarzschild black holes with the same ADM mass, while in the absence of such
rings, they are drastically different from the black hole case.

General Relativity and Quantum Cosmology;High Energy Physics - Theory