Mrk 3 is an early-type galaxy, probably a transition case between E and SO. Analysis of the isophotes clearly shows a disk component along the major axis. A large extended emission line region (EELR) was found. It is confined to a disk along the minor axis, perpendicular to the stellar disk component. The radio-jet of Mrk 3 is almost perpendicular to the stellar disk and has a small inclination only against the EELR.
The ionization mechanism and dynamical state of the EELR was studied from several longslit spectrograms both along and perpendicular to the EELR extension. Both, [OIII]/Hβ and [NII]/Hα clearly indicate that the spectrum of the NLR deviates from HII regions. The line ratios are similar to the values found for the NLR of Mrk 3, indicating that the powerlaw source is responsible for the ionization out to several Kpc.
Off-centre spectrograms indicate that the kinematics is governed by rotation and an additional inflow motion. This accretion flow could have velocities as large as 20 km/sec. It is speculated that the unusually broad and asymmetric lines of the NLR indicate a close interaction with the velocity pattern of the EELR.