Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Ionized Gas and Nuclear Environment in NGC 3783 II. Averaged
  HST/STIS and FUSE Spectra   We present observations of the intrinsic absorption in the Seyfert 1 galaxy
NGC 3783 obtained with the STIS/HST and FUSE. We have coadded multiple STIS and
FUSE observations to obtain a high S/N averaged spectrum spanning 905-1730 A.
The averaged spectrum reveals absorption in O VI, N V, C IV, N III, C III and
the Lyman lines up to LyE in the three blueshifted kinematic components
previously detected in the STIS spectrum (at radial velocities of -1320, -724,
and -548 km/s). The highest velocity component exhibits absorption in Si IV. We
also detect metastable C III* in this component, indicating a high density in
this absorber. We separate the individual covering factors of the continuum and
emission-line sources as a function of velocity in each kinematic component
using the LyA and LyB lines. Additionally, we find that the continuum covering
factor varies with velocity within the individual kinematic components,
decreasing smoothly in the wings of the absorption by at least 60%. The
covering factor of Si IV is found to be less than half that of H I and N V in
the high velocity component. Additionally, the FWHM of N III and Si IV are
narrower than the higher ionization lines in this component. These results
indicate there is substructure within this absorber. We derive a lower limit on
the total column (N_H>=10^{19}cm^{-2}) and ionization parameter (U>=0.005) in
the low ionization subcomponent of this absorber. The metastable-to-total C III
column density ratio implies n_e~10^9 cm^{-3} and an upper limit on the
distance of the absorber from the ionizing continuum of R<=8x10^{17} cm.

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The categories of this paper are: math
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio
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The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: supr-con
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The categories of this paper are: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int