Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: NICS-TNG infrared spectroscopy of NGC1068: the first extragalactic
  measurement of [PII] and a new tool to constrain the origin of [FeII] line
  emission in galaxies   We report 0.9-1.4 micron spectroscopic observations of NGC1068 collected
during the commissioning phase of the near infrared camera spectrometer (NICS)
of the Telescopio Nazionale Galileo (TNG). These yielded the first
extragalactic measurement of [PII] (1.188 micron) line emission. In the central
0.75"x2" the [FeII]/[PII] line-intensity ratio is close to unity, similar to
that measured in the Orion bar and a factor of about 20 smaller than in
supernova remnants. This indicates that most of iron is locked into grains and,
therefore, argues against shock excitation being the primary origin of [FeII]
line emission in the central regions of NGC1068.
  We propose the [FeII]/[PII] ratio as a simple and effective tool to study and
perhaps resolve the long debated questions related to the origin of [FeII] line
emission and, more generally, to constrain the role of shock excitation in
active galaxies.

12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th