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Far-ultraviolet absorption spectra of quasars: How to find missing hot gas and metalsWe show that some high-redshift QSO absorption systems that reveal only the H I Lyman series lines at wavelengths visible from the ground maybe a new class of ultra-high-ionization metal line systems, with metal lines in the far-UV region which is now being explored with satellites. At high temperatures or in intense radiation fields metal systems will not show the usual C IV absorption, and O VI will become the most prominent metal absorber. At still higher ionization, O IV also becomes weak and the strongest metal lines are from Ne VIII, Mg X and Si XII, which have doublets in the rangs 500-800 A. Hence very high ionization metal systems will not show metal lines in existing spectra. Recent X-ray observations show that galaxy halos contain hot gas, so we predict that far-UV spectra of QSOs will also show this gas.
Document ID
19950049373
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Verner, D. A.
(Kapteyn Astronomical Institute Groningen, Netherlands)
Tytler, David
(Univ. of California, San Diego, CA United States)
Barthel, P. D.
(Kapteyn Astronomical Institute Groningen, Netherlands)
Date Acquired
August 16, 2013
Publication Date
July 20, 1994
Publication Information
Publication: The Astrophysical Journal, Part 1
Volume: 430
Issue: 1
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A80972
Funding Number(s)
CONTRACT_GRANT: NAGW-2119
CONTRACT_GRANT: NAG5-26555
Distribution Limits
Public
Copyright
Other

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