A VERY METAL-POOR DAMPED LYMAN-α SYSTEM REVEALED THROUGH THE MOST ENERGETIC GRB 090926A
نویسندگان
چکیده
منابع مشابه
Discovery of the most metal-poor damped Lyman α system
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...
متن کاملThe most metal - poor damped Ly α system at z < 3 : constraints on early nucleosynthesis
To constrain the conditions for very early nucleosynthesis in the Universe we compare the chemical enrichment pattern of an extremely metal-poor damped Lyman α (DLA) absorber with predictions from recent explosive nucleosynthesis model calculations. For this, we have analyzed chemical abundances in the DLA system at z abs = 2.6183 toward the quasar Q0913+072 (z em = 2.785) using public UVES/VLT...
متن کاملThe 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 ...
متن کاملMetallicity Evolution of Damped Lyman-α Systems
According to Pei, Fall & Hauser (1999), the global metallicity evolution of the Universe can be represented by the ratio of the total metal content to the total gas content measured in Damped Lyman–α (DLA) systems (the “column density weighted metallicity” à la Pettini). To minimize dust obscuration effects, a DLA sample with negligible dust content is considered, namely, 50 DLAs with logNHI < ...
متن کاملThe connection between metallicity and metal-line kinematics in (sub-)damped Lyman-α systems
A correlation between the metallicity, [M/H], and rest-frame Mg equivalent width, Wλ2796 r , is found from 49 DLAs and strong sub-DLAs drawn from the literature over the redshift range 0.2 < zabs < 2.6. The correlation is significant at 4.2σ and improves to 4.7σ when the mild evolution of [M/H] with redshift is taken into account. Even when including only the 26 DLAs (i.e. exlcuding sub-DLAs...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2010
ISSN: 0004-637X,1538-4357
DOI: 10.1088/0004-637x/720/1/862