THE CHEMICAL EVOLUTION OF VERY METAL-POOR DAMPED LYαSYSTEMS
نویسندگان
چکیده
منابع مشابه
The most metal-poor damped Lyα systems: insights into chemical evolution in the very metal-poor regime
We present a high spectral resolution survey of the most metal-poor damped Lyα absorption systems (DLAs) aimed at probing the nature and nucleosynthesis of the earliest generations of stars. Our survey comprises 22 systems with iron abundance less than 1/100 solar; observations of seven of these are reported here for the first time. Together with recent measures of the abundances of C and O in ...
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I briefly draw comparisons between the fields of damped Lyα and metal-poor stellar abundances. In particular, I examine their complementary age-metallicity relations and comparisons between the damped Lyα and dwarf galaxy abundance patterns. Regarding the latter, I describe a series of problems concerning associating high z damped Lyα systems with present-day dwarfs.
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We report the discovery and analysis of the most metal-poor damped Lyman α (DLA) system currently known, based on observations made with the Keck HIRES spectrograph. The metal paucity of this system has only permitted the determination of three element abundances: [C/H]=−3.43± 0.06, [O/H]=−3.05± 0.05 and [Si/H]=−3.21± 0.05, as well as an upper limit on the abundance of iron: [Fe/H] ≤ −2.81. Thi...
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High redshift DLA systems suggest that the relative abundances of elements might be roughly solar, although with absolute abundances of more than two orders of magnitude below solar. The result comes from observations of the [SII/ZnII] ratio, which is a reliable diagnostic of the true abundance, and from DLA absorbers with small dust depletion and negligible HII contamination. In particular, in...
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By means of detailed chemical evolution models for galaxies of different morphological types (i.e. spirals, irregular/starburst galaxies and ellipticals) we study the nature of Damped Lyman-α systems. Our concern is to infer which systems represent likely candidates for the DLA population and which do not. By focusing on individual systems, we can derive some constraints on both the nature of t...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2015
ISSN: 1538-4357
DOI: 10.1088/0004-637x/804/2/110