Astronomy and Astrophysics – Astrophysics
Scientific paper
Jun 1991
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991apj...374..496t&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 374, June 20, 1991, p. 496-506.
Astronomy and Astrophysics
Astrophysics
14
H Alpha Line, Helium, Quasars, Red Shift, Sodium, Spectral Line Width, Astronomical Models, Electron Energy, Emission Spectra, Photoionization, Radiative Transfer
Scientific paper
For six QSOs, the H-alpha profile was fit to the position of He I 5876 A and Na I 5890, 5896 doublet. The implied Na I/H-alpha ratio ranged between 0.004 and 0.042. Photoionization models were run with a variety of parameters, including density, column density, ionization parameter, two different incident spectra, and either constant density or constant gas pressure. The models use zone results from Ferland's code Cloudy and solved for the sodium emission. The set of cloud parameters that can produce approximately the observed Na I/H-alpha ratios consist of only the high-density clouds, with n(H) about 10 to the 11th/cu cm and only at column densities N(H) = 10 exp 23.5/sq cm or more. The highest Na I/H-alpha ratios are found in models where the sodium is shielded. The large range of observed Na I/H-alpha ratios implies a corresponding range of cloud conditions.
No associations
LandOfFree
Broad NA D emission in QSOs and the profile of He I 5876 A does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Broad NA D emission in QSOs and the profile of He I 5876 A, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Broad NA D emission in QSOs and the profile of He I 5876 A will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1279465