The structure and dynamics of the early-type resonance ring galaxy IC 4214. I. Observations

The southern galaxy IC 4214 is a bright, nearby example of a multiple ring early-type spiral galaxy with a weak bar. The galaxy shows three strong pseudoring features, including a nuclear ring, an inner ring, and a prominent R-1' outer ring, each with distinctive characteristics. The galaxy is important because it is a classic resonance ring galaxy where the ring features can be linked to specific orbital resonances with the bar. We present in this paper a detailed UBVIH study of its photometric structure and a Fabry-Perot study of its kinematics to set the stage for a dynamical model in a separate paper. Despite the early Hubble type, ionized gas is well. distributed in the inner disk regions, providing a well-sampled velocity field. Rapid rotation is found in the vicinity of the nuclear ring, where the rotation curve reaches a maximum, and the rotation velocities drop off somewhat with increasing radius in the outer regions. Noncircular motions are clearly seen in the observed velocity held. Analysis of both the velocity held and the shapes of isophotes give discrepant values for the inclination of the system, ranging from 47 degrees to 50 degrees from photometry to 55 degrees to 58 degrees from kinematics. A likely value of the inclination could be 52 degrees if the inner and outer rings are intrinsically elongated and aligned perpendicular to each other.