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High redshift quasars and high metallicitiesA large-scale code called Cloudy was designed to simulate non-equilibrium plasmas and predict their spectra. The goal was to apply it to studies of galactic and extragalactic emission line objects in order to reliably deduce abundances and luminosities. Quasars are of particular interest because they are the most luminous objects in the universe and the highest redshift objects that can be observed spectroscopically, and their emission lines can reveal the composition of the interstellar medium (ISM) of the universe when it was well under a billion years old. The lines are produced by warm (approximately 10(sup 4)K) gas with moderate to low density (n less than or equal to 10(sup 12) cm(sup -3)). Cloudy has been extended to include approximately 10(sup 4) resonance lines from the 495 possible stages of ionization of the lightest 30 elements, an extension that required several steps. The charge transfer database was expanded to complete the needed reactions between hydrogen and the first four ions and fit all reactions with a common approximation. Radiative recombination rate coefficients were derived for recombination from all closed shells, where this process should dominate. Analytical fits to Opacity Project (OP) and other recent photoionization cross sections were produced. Finally, rescaled OP oscillator strengths were used to compile a complete set of data for 5971 resonance lines. The major discovery has been that high redshift quasars have very high metallicities and there is strong evidence that the quasar phenomenon is associated with the birth of massive elliptical galaxies.
Document ID
19970013666
Acquisition Source
Goddard Space Flight Center
Document Type
Contractor Report (CR)
Authors
Ferland, Gary J.
(Kentucky Univ. Lexington, KY United States)
Date Acquired
September 6, 2013
Publication Date
March 27, 1997
Subject Category
Astrophysics
Report/Patent Number
NASA-CR-203971
NAS 1.26:203971
Report Number: NASA-CR-203971
Report Number: NAS 1.26:203971
Accession Number
97N17382
Funding Number(s)
CONTRACT_GRANT: NAGw-3315
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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