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HD 179504


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The emission spectrum of active galactic nuclei. II - High column density photoionization models and low ionization lines
Current one-component models of the broad line region of quasars fail toexplain the strength of low ionization lines. A two-componentphotoionization model where the high and low ionization lines areallowed to arise from different kinds of clouds is explored. A spectraldistribution of the incident radiation which tends to overestimate theX-ray flux around 3 keV is adopted in order to enhance the extent andthe heating of the excited H I region. After discussing the influence ofseveral parameters, it is concluded that the model is still unable toexplain the observed ratio Fe II/H? and that another kind of cloud,presumably not heated by photoionization, is needed to emit Fe II.

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Observation and Astrometry data

Constellation:ぼうえんきょう座
Right ascension:19h15m43.94s
Declination:-53°51'42.2"
Apparent magnitude:8.91
Distance:117.925 parsecs
Proper motion RA:30.8
Proper motion Dec:-96.1
B-T magnitude:9.4
V-T magnitude:8.951

Catalogs and designations:
Proper Names   (Edit)
HD 1989HD 179504
TYCHO-2 2000TYC 8760-802-1
USNO-A2.0USNO-A2 0300-35546305
HIPHIP 94660

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