  We carry out a population study of magnetized radio filaments in the Galactic
center using MeerKAT data by focusing on the spacing between the filaments that
are grouped. The morphology of a sample of 43 groupings containing 174
magnetized radio filaments are presented. Many grouped filaments show
harp-like, fragmented cometary tail-like, or loop-like structures in contrast
to many straight filaments running mainly perpendicular to the Galactic plane.
There are many striking examples of a single filament splitting into two prongs
at a junction, suggestive of a flow of plasma along the filaments. Spatial
variations in spectral index, brightness, bending and sharpening along the
filaments indicate that they are evolving on a 10^{5-6}-year time scale. The
mean spacings between parallel filaments in a given grouping peaks at
$\sim16''$. We argue by modeling that the filaments in a grouping all lie on
the same plane and that the groupings are isotropically oriented in 3D space.
One candidate for the origin of filamentation is interaction with an obstacle,
which could be a compact radio source, before a filament splits and bends into
multiple filaments. In this picture, the obstacle or sets the length scale of
the separation between the filaments. Another possibility is synchrotron
cooling instability occurring in cometary tails formed as a result of the
interaction of cosmic-ray driven Galactic center outflow with obstacles such as
stellar winds. In this picture, the mean spacing and the mean width of the
filaments are expected to be a fraction of a parsec, consistent with observed
spacing.
