Revealing the velocity structure of the filamentary nebula in NGC 1275
  in its entirety
  We have produced for the first time a detailed velocity map of the giant
filamentary nebula surrounding NGC 1275, the Perseus cluster's brightest
galaxy, and revealed a previously unknown rich velocity structure across the
entire nebula. We present new observations of the low-velocity component of
this nebula with the optical imaging Fourier transform spectrometer SITELLE at
CFHT. With its wide field of view ($\sim$11'$\times$11'), SITELLE is the only
integral field unit spectroscopy instrument able to cover the 80 kpc$\times$55
kpc (3.8'$\times$2.6') large nebula in NGC 1275. Our analysis of these
observations shows a smooth radial gradient of the [N
II]$\lambda$6583/$\text{H} \alpha$ line ratio, suggesting a change in the
ionization mechanism and source across the nebula, while the dispersion profile
shows a general decrease with increasing distance from the AGN at up to $\sim
10$ kpc. The velocity map shows no visible general trend or rotation,
indicating that filaments are not falling uniformly onto the galaxy, nor being
pulled out from it. Comparison between the physical properties of the filaments
and Hitomi measurements of the X-ray gas dynamics in Perseus are also explored.
