| Abstract
| - CCD spectroscopic observations from [Ne v] λ3425 Å to [S iii] λ9532 υ of the nucleus and circumnuclear region of the Seyfert 1 NGC 4253 are presented. The nucleus shows circumnuclear emission which is elongated 1.5 kpc to the north-east; the spectrum of this extranuclear emission is well fitted by H ii region models with effective temperatures of 50 000 K. The kinematics of the high-excitation gas is perturbed with respect to the low-ionization gas, showing radial motions compatible with an outflow wind. The nucleus is a strong Fe ii emitter, and its spectrum shows high-excitation lines, such as [Fe vii] λ6086 Å and [Fe x] λ6374 Å, which are produced by photoionization in the coronal-line region. Lines produced in high-density and low-ionization conditions, such as O i λ8446 Å and Mg ii λ9220 Å, are also detected; we show that these lines are produced by fluorescence with Lyβ. The near-infrared Ca ii triplet, detected in emission and in absorption, and the Fe u emission are discussed in terms of the starburst model developed by Terlevich and collaborators.
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