On the He II Gunn–Peterson effect and the He II forest
نویسندگان
چکیده
منابع مشابه
The He II Lyman alpha forest : evaluation of simulated data
Using an artificial H I Lyα spectrum we simulate the corresponding He II forest with fixed values of η and a Doppler parameter consisting of a thermal and a turbulent part. In addition metal lines with line strengths and line density as expected in the case of HS 1700+6416 are superimposed. FUSE-like noise is added. The analysis of the simulated spectra in terms of Doppler profiles recovers the...
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U V photoelectron spectra of the title com pounds are rep orted . A ssignm ents are m ade with the help of H e(I)/H e(II) intensity differences, shift effects upon substitu tion and com parison with re la ted m olecules. Previously draw n conclusions about the electronic structure of similar com plexes also hold for the com pounds. It is indicated that the ionization energy for the sym m etri...
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Primordial baryonic matter in the vast intergalactic space may be traced with Lyα resonance absorption by neutral hydrogen and singly ionized helium. The wavelengthaveraged He ii opacity shortward of 304(1+z) Å, as measured by low-resolution UV spectroscopy, is at least 4.5 times the H i opacity shortward of 1216(1+z) Å. While a part of the He ii opacity arises from the intergalactic regions th...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1993
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/262.1.273