Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Infrared FeII Emission in Narrow-Line Seyfert 1 Galaxies   We obtained 0.8-2.4 micron spectra at a resolution of 320 km/s of four
narrow-line Seyfert 1 galaxies in order to study the near-infrared properties
of these objects. We focus on the analysis of the FeII emission in that region
and the kinematics of the low-ionization broad lines. We found that the 1
micron FeII lines (9997 A, 10501 A, 10863 A and 11126 A) are the strongest FeII
lines in the observed interval. For the first time, primary cascade lines of
FeII arising from the decay of upper levels pumped by Ly-alpha fluorescence are
resolved and identified in active galactic nuclei. Excitation mechanisms
leading to the emission of the 1 micron FeII features are discussed. A
combination of Ly-alpha fluorescence and collisional excitation are found to be
the main contributors. The flux ratio between near-IR FeII lines varies from
object to object, in contrast to what is observed in the optical region. A good
correlation between the 1 micron and optical FeII emission is found. This
suggests that the upper z4Fo and z4Do levels from which the bulk of the optical
lines descend are mainly populated by the transitions leading to the 1 micron
lines. The width and profile shape of FeII 11127, CaII 8642 and OI 8446 are
very similar but significantly narrower than Pa-beta, giving strong
observational support to the hypothesis that the region where FeII, CaII and OI
are produced are co-spatial, interrelated kinematically and most probably
located in the outermost portion of the BLR.

18
The categories of this paper are: econ
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom