HALOGAS observations of NGC 4414: fountains, interaction, and ram
  pressure
  We present deep HI imaging of the nearby spiral galaxy NGC 4414, taken as
part of the Westerbork HALOGAS (Hydrogen Accretion in LOcal GAlaxieS) survey.
The observations show that NGC 4414 can be characterized by a regularly
rotating inner HI disk, and a more disturbed outer disk. Modeling of the
kinematics shows that the outer disk is best described by a U-shaped warp. Deep
optical imaging also reveals the presence of a low surface brightness stellar
shell, indicating a minor interaction with a dwarf galaxy at some stage in the
past. Modeling of the inner disk suggests that about 4 percent of the inner HI
is in the form of extra-planar gas. Because of the the disturbed nature of the
outer disk, this number is difficult to constrain for the galaxy as a whole.
These new, deep observations of NGC 4414 presented here show that even
apparently undisturbed galaxies are interacting with their environment.
