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相关论文: The First Detection of Cobalt in a Damped Lyman Al…

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The study of elemental abundances in Damped Lyman Alpha systems (DLAs) at high redshift represents one of our best opportunities to probe galaxy formation and chemical evolution at early times. By coupling measurements made in high z DLAs…

天体物理学 · 物理学 2016-01-27 Sara L. Ellison , Sean G. Ryan , Jason X. Prochaska

We present the first detection of carbon monoxide (CO) in a damped Lyman-alpha system (DLA) at z_abs =2.41837 toward SDSS J143912.04+111740.5. We also detected H_2 and HD molecules. The measured total column densities (in log units) of H I,…

天体物理学 · 物理学 2020-12-23 R. Srianand , P. Noterdaeme , C. Ledoux , P. Petitjean

We report on the first Cosmic Origins Spectrograph (COS) observations of damped and sub-damped Lyman-alpha (DLA) systems discovered in a new survey of the gaseous halos of low-redshift galaxies. From observations of 37 sightlines, we have…

We have investigated chemical evolution in the young universe by analysing the detailed chemical enrichment pattern of a metal-rich galaxy at high redshift. The recent detection of over 20 elements in the gas-phase of a damped Lyman-alpha…

天体物理学 · 物理学 2009-11-10 Yeshe Fenner , Jason X. Prochaska , Brad K. Gibson

We explore the redshift evolution of the metal content of damped Lyman alpha systems (DLAs) with new observations of four absorbers at z < 1.5 . The main conclusion is that the column density--weighted mean metallicity, [<Zn/H>] = -1.03 +/-…

天体物理学 · 物理学 2009-10-30 Max Pettini , Sara L. Ellison , Charles C. Steidel , David V. Bowen

We report results on the incidence and cosmological mass density of damped Lyman-alpha (DLA) systems at redshifts less that 1.65. We used HST and an efficient non-traditional (but unbiased) survey technique to discover DLA systems at…

天体物理学 · 物理学 2009-10-31 Sandhya M. Rao , David A. Turnshek

We report the first discovery of a QSO damped Ly-alpha (DLA) system by the GALEX satellite. The system was initially identified as an MgII absorption-line system (z_abs=1.028) in the spectrum of SDSS QSO J0203-0910 (z_em=1.58). The presence…

宇宙学与河外天体物理 · 物理学 2015-05-13 Eric Monier , David Turnshek , Sandhya Rao , Anja Weyant

We present the results of a series of imaging and spectroscopic observations aimed at identifying and studying the galaxy responsible for the z = 3.38639 damped lya system in the z = 3.61 QSO Q0201+1120. We find that the DLA is part of a…

天体物理学 · 物理学 2016-08-30 Sara L. Ellison , Max Pettini , Charles C. Steidel , Alice E. Shapley

We compare the properties of a sample of local (z=0) gas-rich galaxies studied in 21 cm emission to a sample of 13 low-redshift (z < 1) damped Lyman alpha (DLA) galaxies identified as the counterparts of low-redshift DLA systems found in…

天体物理学 · 物理学 2007-05-23 David A. Turnshek , Sandhya M. Rao , Daniel B. Nestor

We report the discovery and analysis of the most metal-poor damped Lyman-alpha (DLA) system currently known, based on observations made with the Keck HIRES spectrograph. The metal paucity of this system has only permitted the determination…

宇宙学与河外天体物理 · 物理学 2017-01-13 Ryan Cooke , Max Pettini , Charles C. Steidel

We report on the results of a search for CO(3-2) emission from the galaxy counterpart of a high-metallicity Damped Ly-alpha Absorber (DLA) at z=2.5832 towards the quasar Q0918+1636. We do not detect CO emission from the previously…

The formation and evolution of galaxies require large reservoirs of cold, neutral gas. The damped Lya systems (DLAs), seen in absorption towards distant quasars and gamma-ray bursts, are predicted to be the dominant reservoirs for this gas.…

星系天体物理 · 物理学 2015-10-28 Jeff Cooke , John O'Meara

We present a low-redshift (z=0.029) Damped Lyman-alpha (DLA) system in the spectrum of a background Quasi-Stellar Object (QSO). The DLA is associated with an interacting galaxy pair within a galaxy group. We detected weak Lyman-alpha…

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…

天体物理学 · 物理学 2007-05-23 Celine Peroux

We report the discovery of the first 'ghostly' damped Ly$\alpha$ absorption system (DLA), which is identified by the presence of absorption from strong low-ion species at $z_{\rm abs}=1.70465$ along the line of sight to the quasar…

We study the nature of damped Lya absorption (DLA) systems at z<=1 using a sample of 11 DLA galaxies, for which accurate redshift measurements are available. We demonstrate that the precision of photometric redshifts is sufficient for…

天体物理学 · 物理学 2009-11-10 Hsiao-Wen Chen , Kenneth M. Lanzetta

The evolution of the metallicity of damped Lyman alpha systems (DLAs) is investigated in order to understand the nature of these systems. The observational data on chemical abundances of DLAs are analysed with robust statistical methods,…

天体物理学 · 物理学 2009-11-07 Gustavo A. Lanfranchi , Amancio Friaca

In order to characterize Damped Lyman Alpha systems (DLAs) potentially hosting first stars, we present a novel approach to investigate DLAs in the context of Milky Way (MW) formation, along with their connection with the most metal-poor…

宇宙学与河外天体物理 · 物理学 2015-06-03 Stefania Salvadori , Andrea Ferrara

A powerful technique to trace the signatures of the first stars is through the metal enrichment in concentrated reservoirs of hydrogen, such as the damped Lyman-alpha absorbers (DLAs) in the early universe. We conducted a survey aimed at…

星系天体物理 · 物理学 2025-10-01 Jianghao Huyan , Varsha P. Kulkarni , Suraj Poudel , Nicolas Tejos , Celine Peroux , Sebastian Lopez

We show that the recently observed elemental abundance pattern of the carbon-rich metal-poor Damped Lyman $\alpha$ (DLA) system is in excellent agreement with the nucleosynthesis yields of faint core-collapse supernovae of primordial stars.…

宇宙学与河外天体物理 · 物理学 2015-05-20 Chiaki Kobayashi , Nozomu Tominaga , Ken'ich Nomoto
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