About Poynting vector in axially symmetric stationary spacetimes
  We dispose of some objections raised by Manko et al. (gr-qc/0604091) on a recently published paper on the role of Poynting vector in the ocurrence of vorticity in electrovaccum spacetimes (2006, Class. Quantum Grav. 23, 2395) 
Leonardo A. Pachon and Jorge A. Rueda