  High resolution observations of solar filaments suggest the presence of
groups of prominence threads, i.e. the fine-structures of prominences, which
oscillate coherently (in phase). In addition, mass flows along threads have
been often observed. Here, we investigate the effect of mass flows on the
collective fast and slow nonadiabatic magnetoacoustic wave modes supported by
systems of prominence threads. Prominence fine-structures are modeled as
parallel, homogeneous and infinite cylinders embedded in a coronal environment.
The magnetic field is uniform and parallel to the axis of threads.
Configurations of identical and nonidentical threads are both explored. We
apply the T-matrix theory of acoustic scattering to obtain the oscillatory
frequency and the eigenfunctions of linear magnetosonic disturbances. We find
that the existence of wave modes with a collective dynamics, i.e. those that
produce significant perturbations in all threads, is only possible when the
Doppler-shifted individual frequencies of threads are very similar. This can be
only achieved for very particular values of the plasma physical conditions and
flow velocities within threads.
