QUASARS PROBING QUASARS. VI. EXCESS H I ABSORPTION WITHIN ONE PROPER Mpc OFz∼ 2 QUASARS
نویسندگان
چکیده
منابع مشابه
Quasars Probing Quasars I: Optically Thick Absorbers near Luminous Quasars
With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar’s environment in absorption. We search 149 moderate resolution background quasar spectra, from Gemini, Keck, the MMT, and the SDSS to survey Lyman Limit Systems (LLSs) and Damped Lyα systems (DLAs) in the vicinity of 1.8 < z < 4.0 luminous foreground quasars. A sample of 27...
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With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar’s environment in absorption. We used a sample of 17 Lyman limit systems with column density NHI > 10 19 cm selected from 149 projected quasar pair sightlines, to investigate the clustering pattern of optically thick absorbers around luminous quasars at z ∼ 2.5. Specifically...
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Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium (D or 2H), 3He, 4He and 7Li during the first few minutes of the universe. In this review we concentrate on recent data which give the primordial deuterium (D) abundance. We have measured the primordial D/H in gas with very nearly primordial abundances. We use the Lyman series absorption lines seen in the spectra of q...
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Galaxies hosting z ∼ 2 quasars are the high-z progenitors of today’s massive ‘red-and-dead’ galaxies. With close pairs of quasars at different redshifts, a background quasar can be used to study a foreground quasar’s halo gas in absorption, providing a wealth of information about feedback, quenching, and the physics of massive galaxy formation. We present a Keck/HIRES spectrum of the bright bac...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2013
ISSN: 0004-637X,1538-4357
DOI: 10.1088/0004-637x/776/2/136