| Abstract | Aims.We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN) of all degrees of activity in the wavelength interval of 0.8-2.4 μm, including the fluxes of the observed emission lines. We analyze the spectroscopic properties of the continuum and emission line spectra of the sources.
Methods: . In order to exclude aperture and seeing effects we used near-infrared spectroscopy in the short cross-dispersed mode (SXD, 0.8-2.4 μm), taking the JHK-bands spectra simultaneously.
Results: .We present the most extensive NIR spectral atlas of AGN to date. This atlas offers a suitable database for studying the continuum and line emission properties of these objects in a region full of interesting features. The shape of the continuum of QSOs and Sy 1's are similar, being essentially flat in the H and K bands, while a strong variation is found in the J band. In Seyfert 2 galaxies, the continuum in the Fλ × λ space smoothly decreases in flux from 1.2 μm redwards in almost all sources. In J, it smoothly rises bluewards in some sources, while in others a small decrease in flux is observed. The spectra are dominated by strong emission features of H I, He I, He II, [S III] and by conspicuous forbidden lines of low and high ionization species. Molecular lines of H{2} are common features of most objects. The absence of O I and Fe II lines in Seyfert 2 galaxies and the smaller FWHM of these lines relative to that of H I in the Seyfert 1 give observational support to the fact that they are formed in the outermost portion of the broad-line region. The[P II] and coronal lines are detected for all degrees of activity. The [Fe II] 12 570 Å/16 436 Å line ratio becomes a reliable reddening indicator for the narrow-line region of Seyfert galaxies.
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