Molecules in Damped Lyα Systems: Spatial Distribution
نویسندگان
چکیده
منابع مشابه
DAMPED Lyα SYSTEMS
Observations of damped Lyα systems offer a unique window on the neutral-gas reservoirs that gave rise to galaxies at high redshifts. This review focuses on critical properties such as the H I and metal content of the gas and on independent evidence for star formation. Together, these provide an emerging picture of gravitationally bound objects in which accretion of gas from the IGM replenishes ...
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We report evidence for a bimodality in damped Lyα systems (DLAs). Using [C II] 158 μm cooling rates, lc, we find a distribution with peaks at lc=10 −27.4 and 10 ergs s H separated by a trough at l c ≈ 10 −27.0 ergs s H. We divide the sample into ‘low cool’ DLAs with lc ≤ l crit c and ‘high cool’ DLAs with lc > l crit c and find the Kolmogorv-Smirnov probabilities that velocity width, metallicit...
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We measure feedback (heating rates) in damped Lyα systems (DLAs) from the cooling rate of the neutral gas. Since cooling occurs through [C II] 158 μm emission, we infer cooling from C II 1335.7 absorption lines detected with HIRES on the Keck I telescope. The inferred heating rates are 30 times lower than for the Galaxy ISM. At z ≈ 2.8 the implied star formation rate per unit area is logψ∗=−2.4...
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Although quasar absorbers, and in particular Damped Lyman-alpha systems (DLAs) have proven a valuable tool to study the early Universe, their exact nature is so far poorly constrained. It has been suggested that outflows in galaxies might account for at least part of the DLA population. Observational evidences and models in support of this hypothesis are reviewed, including recent observations ...
متن کاملChemical Abundances in the Damped Lyα Systems
I introduce and review the data and analysis techniques used to measure abundances in the damped Lyα systems, quasar absorption-line systems associated with galaxies in the early Universe. The observations and issues associated with their abundance analysis are very similar to those of the Milky Way’s interstellar medium. We measure gas-phase abundances and are therefore subject to the effects ...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 2004
ISSN: 0074-1809
DOI: 10.1017/s0074180900197712