  Understanding the initial properties of star-forming material and how they
affect the star formation process is key. From an observational point of view,
the feedback from young high-mass stars on future star formation properties is
still poorly constrained. In the framework of the IRAM 30m ORION-B large
program, we obtained observations of the translucent and moderately dense gas,
which we used to analyze the kinematics over a field of 5 deg^2 around the
filamentary structures. We used the ROHSA algorithm to decompose and de-noise
the C18O(1-0) and 13CO(1-0) signals by taking the spatial coherence of the
emission into account. We produced gas column density and mean velocity maps to
estimate the relative orientation of their spatial gradients. We identified
three cloud velocity layers at different systemic velocities and extracted the
filaments in each velocity layer. The filaments are preferentially located in
regions of low centroid velocity gradients. By comparing the relative
orientation between the column density and velocity gradients of each layer
from the ORION-B observations and synthetic observations from 3D kinematic toy
models, we distinguish two types of behavior in the dynamics around filaments:
(i) radial flows perpendicular to the filament axis that can be either inflows
(increasing the filament mass) or outflows and (ii) longitudinal flows along
the filament axis. The former case is seen in the Orion B data, while the
latter is not identified. We have also identified asymmetrical flow patterns,
usually associated with filaments located at the edge of an HII region. This is
the first observational study to highlight feedback from HII regions on
filament formation and, thus, on star formation in the Orion B cloud. This
simple statistical method can be used for any molecular cloud to obtain
coherent information on the kinematics.
