  In this paper, we study the coupled Keller-Segel-Navier-Stokes system, which
models chemotaxis occuring in ambient viscous fluid. We consider this
nonlinear, nonlocal system on a periodic strip, equipped with homogeneous
Neumann boundary conditions for the Keller-Segel part and no-slip boundary
condition for the fluid part. We prove the simultaneous space-time analyticity
of the solution up to the boundary based on energy methods.
