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相关论文: Ionized Gas in Damped Lyman Alpha Protogalaxies: I…

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We test semi-analytic models for galaxy formation with accurate kinematic data of damped Lyman alpha protogalaxies (DLAs) presented in the companion paper I. The models envisage centrifugally supported exponential disks at the centers of…

天体物理学 · 物理学 2009-10-31 Arthur M. Wolfe , Jason X. Prochaska

We investigate a model for the high-ionization state gas associated with observed damped Lyman-alpha systems, based on a semi-analytic model of galaxy formation set within the paradigm of hierarchical structure formation. In our model, the…

天体物理学 · 物理学 2009-11-07 Ariyeh H. Maller , Jason X. Prochaska , Rachel S. Somerville , Joel R. Primack

We demonstrate in this paper that the velocity widths of the neutral gas in Damped Ly Alpha (DLA) systems are inconsistent with these systems originating in gas disks of galaxies similar to those seen in the local Universe. We examine the…

We examine the kinematic structure of Damped Lyman-alpha Systems (DLAs) in a series of cosmological hydrodynamic simulations using the AREPO code. We are able to match the distribution of velocity widths of associated low ionisation metal…

星系天体物理 · 物理学 2015-01-08 Simeon Bird , Martin Haehnelt , Marcel Neeleman , Shy Genel , Mark Vogelsberger , Lars Hernquist

The velocity profiles of weak metal absorption lines can be used to observationally probe the kinematic state of gas in damped Lyman-alpha systems. Prochaska and Wolfe have argued that the flat distribution of velocity widths combined with…

天体物理学 · 物理学 2009-10-31 Ariyeh H. Maller , Rachel S. Somerville , Jason X. Prochaska , Joel R. Primack

We probe the physical conditions in high redshift galaxies, specifically, the Damped Lyman-alpha Systems (DLAs) using neutral carbon (CI) fine structure lines and molecular hydrogen (H2). We report five new detections of CI and analyze the…

宇宙学与河外天体物理 · 物理学 2015-05-19 Regina A. Jorgenson , Arthur M. Wolfe , J. Xavier Prochaska

We derive the statistical properties of neutral gas at redshifts 0.11<z<1.65 from UV measurements of quasar Lyman alpha absorption lines corresponding to 369 MgII systems with $W^{\lambda2796}_{0} \ge 0.3$ \AA. In addition to the 41 damped…

星系天体物理 · 物理学 2017-08-23 Sandhya M. Rao , David A. Turnshek , Gendith M. Sardane , Eric M. Monier

A new method is used to measure the physical conditions of the gas in damped Lyman-alpha systems (DLAs). Using high resolution absorption spectra of a sample of 80 DLAs, we are able to measure the ratio of the upper to lower fine-structure…

星系天体物理 · 物理学 2015-06-23 Marcel Neeleman , J. Xavier Prochaska , Arthur. M. Wolfe

We present the first results of an ongoing program to investigate the kinematic characteristics of high redshift damped lya systems. Because damped lya systems are widely believed to be the progenitors of current massive galaxies, an…

天体物理学 · 物理学 2009-10-30 Jason X. Prochaska , Arthur M. Wolfe

We investigate the physical processes occuring in the multiphase gas of a damped Ly\alpha system (DLA). We base our analysis on a high quality Keck HIRES spectrum of the QSO J1211+0422 in which a DLA is detected at z=2.377. There is little…

天体物理学 · 物理学 2009-11-13 N. Lehner , J. C. Howk , J. X. Prochaska , A. M. Wolfe

We investigate the properties of damped Lyman-alpha systems (DLAS) in semi-analytic models, focusing on whether the models can reproduce the kinematic properties of low-ionization metal lines described by Prochaska & Wolfe (1997b, 1998). We…

天体物理学 · 物理学 2007-05-23 Ariyeh H. Maller , Jason X. Prochaska , Rachel S. Somerville , Joel R. Primack

We present a study of C IV absorption in a sample of 63 damped Lyman-alpha (DLA) systems and 11 sub-DLAs in the redshift range 1.75<z_abs<3.61, using a dataset of high-resolution (6.6 km/s FWHM), high signal-to-noise VLT/UVES spectra.…

天体物理学 · 物理学 2009-11-13 Andrew J. Fox , Cédric Ledoux , Patrick Petitjean , Raghunathan Srianand

We present results for 19 "Lyman Break Analogs" (LBAs) observed with Keck/OSIRIS with an AO-assisted spatial resolution of less than 200 pc. We detect satellites/companions, diffuse emission and velocity shear, all with high signal-to-noise…

In this paper we analyze the kinematics, chemistry, and physical properties of a sample of the most metal-poor damped Lyman-alpha systems (DLAs), to uncover their links to modern-day galaxies. We present evidence that the DLA population as…

星系天体物理 · 物理学 2015-08-04 Ryan Cooke , Max Pettini , Regina A. Jorgenson

We discuss our recent results on the statistical properties of damped Lyman alpha systems (DLAs) at low redshift (z<1.65) (Rao & Turnshek 2000). Contrary to expectations, we found that the cosmological neutral gas mass density as traced by…

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

Recent observations from the James Webb Space Telescope (JWST) have revealed proximate damped Lyman-$\alpha$ systems (PDLAs) in the foreground of high redshift galaxies ($z \gt 5$), which have been interpreted as neutral circumgalactic…

星系天体物理 · 物理学 2026-05-20 Maya Steen , Kristian Finlator , Samir Kušmić , Ezra Huscher

Previously we have shown that it is possible to account for the kinematic properties of damped Lyman alpha systems (DLAS) in the context of semi-analytic models. In these models, hierarchical structure formation is approximated by…

天体物理学 · 物理学 2007-05-23 Ariyeh H. Maller , Rachel S. Somerville , Jason X. Prochaska , Joel R. Primack

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 present results from a survey of galaxies in the fields of six z>3 Damped Lyman alpha systems (DLAs) using the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT). We report a high detection rate of up to ~80% of…

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