  Dynamical Chern-Simons (dCS) gravity has been attracting plenty of attentions
due to the fact that it is a parity-violating modified theory of gravity that
corresponds to a well-posed effective field theory in weak coupling
approximation. In particular, a rotating black hole in dCS gravity is in
contrast to the general relativistic counterparts. In this paper, we revisit
the shadow of analytical rotating black hole spacetime in dCS modified gravity,
based on which we study the shadow observables, discuss the constraint on the
model parameters from the Event Horizon Telescope (EHT) observations, and
analyze the real part of quasi-normal modes (QNMs) in the eikonal limit. In
addition, we explore the deflection angle in weak gravitational field limit
with the use of Gauss-Bonnet theorem. We find that the shadow related physics
and the weak gravitational lensing effect are significantly influenced by the
CS coupling, which could provide theoretical predictions for a future test of
the dCS theory with EHT observations.
