H{\alpha} Kinematics of S4G spiral galaxies-I. NGC 864
  We present a study of the kinematics of the isolated spiral galaxy NGC 864,
using H{\alpha} Fabry-Perot data obtained with the GH{\alpha}FaS instrument at
the William Herschel Telescope in La Palma, complemented with images at 3.6
{\mu}m, in the R band and in H{\alpha} filter, and integral field spectroscopic
data. The resulting data cubes and velocity maps allow the study of the
kinematics of the galaxy, including in-depth investigations of the rotation
curve, velocity moment maps, velocity residual maps, gradient maps and
position-velocity diagrams. We find asymmetries in the velocity field in the
bar zone, caused by non-circular motions, probably in response to the potential
of the bar. We also find a flat-profile bar, in agreement with the strong bar,
with the grand design spiral pattern, and with the gap between the ends of the
bar and the start of the spiral arms. We quantify the rate of massive star
formation, which is concentrated in the two spiral arms.
