Wake-field excitations in a multi-component dusty plasma

The wake-field excited by a test charge moving through a multicomponent dus ty plasma is calculated by using the fluid as well as the Vlasov-Poisson mo del. It is shown that the ion-wake field may be oscillatory (V-t < C-DA), c onstant (V-t <similar to> C-DA), or exponentially decreasing (V-t > C-DA), depending upon the test charge velocity V-t relative to the dust acoustic s peed C-DA. Numerical results for the wake-field are presented for different test charge velocities. The work has relevance in space and astrophysical plasmas.