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相关论文: ALPACA: A New Semi-Analytic Model for Metal Absorp…

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We present analytical approximations for calculating the scattering, absorption and escape of nonionizing photons from a spherically symmetric two-phase clumpy medium, with either a central point source of isotropic radiation, a uniform…

天体物理学 · 物理学 2009-10-31 Frank Varosi , Eli Dwek

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 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

The Circum-Galactic Medium (CGM) can be probed through the analysis of absorbing systems in the line-of-sight to bright background quasars. We present measurements of the metallicity of a new sample of 15 sub-damped Lyman-$\alpha$ absorbers…

We report the serendipitous detection of a 0.2 L$^*$, Lyman-$\alpha$ emitting galaxy at redshift 2.5 at an impact parameter of 50 kpc from a bright background QSO sightline. A high-resolution spectrum of the QSO reveals a partial…

We present a spectroscopic study of six damped Lya absorption (DLA) systems at z<0.65, based on moderate-to-high resolution spectra of the galaxies responsible for the absorbers. Combining known metallicity measurements of the absorbers…

天体物理学 · 物理学 2009-11-10 Hsiao-Wen Chen , Robert C. Kennicutt , Michael Rauch

We use our high resolution He-lamp based, tunable laser-based ARPES measurements and density functional theory calculations to study the electronic properties of LaBi, a binary system that was proposed to be a member of a new family of…

We investigate the properties of damped Ly{\alpha} absorption systems (DLAs) in semi-analytic models of galaxy formation, including partitioning of cold gas in galactic discs into atomic, molecular, and ionized phases with a molecular…

宇宙学与河外天体物理 · 物理学 2015-06-16 Michael Berry , Rachel S. Somerville , Marcel R. Haas , Eric Gawiser , Ari Maller , Gergo Popping , Scott C. Trager

The metal absorption lines found in association with \lya absorbers of moderate to high HI column density contain valuable information about the metallicity and ionization conditions within the absorbers and offer a stronger test of models…

天体物理学 · 物理学 2016-08-30 Uffe Hellsten , Lars Hernquist , Neal Katz , David Weinberg

Context: From redshift 6 to redshift $\approx$ 4 galaxies grow rapidly from low mass galaxies towards the more mature massive galaxies we see at the cosmic noon. Growth via gas accretion and mergers undoubtedly shape this evolution -…

We present a survey undertaken with the Atacama Large Millimeter/submillimeter Array (ALMA) to study the galaxies associated with a representative sample of 16 damped Ly-alpha absorbers (DLAs) at z~4.1-4.5, using the [CII]-158-micron…

星系天体物理 · 物理学 2025-04-08 Marcel Neeleman , Nissim Kanekar , J. Xavier Prochaska , Marc A. Rafelski , Lordrick A. Kahinga

We theoretically demonstrate the fundamental limit in volume for given materials (e.g. Si, a-Si, CdTe) to fully absorb the solar radiation above bandgap, which we refer as solar superabsorption limit. We also point out the general…

光学 · 物理学 2013-12-03 Yiling Yu , Lujun Huang , Linyou Cao

We present constrained radiative transfer calculations of Lyman Alpha (Lya) photons propagating through clumpy, dusty, large scale outflows, and explore whether we can quantitatively explain the Lya halos that have been observed around…

宇宙学与河外天体物理 · 物理学 2015-06-04 Mark Dijkstra , Roban Hultman Kramer

The central structure in three of the brightest unlensed z=3-4 submillimeter galaxies are investigated through 0.015" - 0.05" (120 -- 360~pc) 860 micron continuum images obtained using the Atacama Large Millimeter/submillimeter Array…

Using the Atacama Large Millimeter/sub-millimeter Array, we have detected CO(3-2) line and far-infrared continuum emission from a galaxy associated with a high-metallicity ([M/H] = -0.27) damped Ly-alpha absorber (DLA) at z =2.19289. The…

We characterize the properties of the intergalactic medium (IGM) around a sample of galaxies extracted from state-of-the-art hydrodynamical simulations of structure formation in a cosmological volume of 25 Mpc comoving at $z\sim 2$. The…

星系天体物理 · 物理学 2018-07-03 C. Mongardi , M. Viel , V. D'Odorico , T. -S. Kim , P. Barai , G. Murante , P. Monaco

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

In a hierarchical cosmogony present-day galaxies build up by continuous merging of smaller structures. At a redshift of three the matter content of a typical present-day galaxy is split into about ten individual protogalactic clumps.…

天体物理学 · 物理学 2007-05-23 Martin G. Haehnelt

In this paper, we present a new method to constrain the metallicities of high redshift damped Ly$\alpha$ (DLA) absorbers using observed extinction curves. This is the first time such an approach is employed to constrain the metallicities of…

星系天体物理 · 物理学 2021-03-03 Hassan Fathivavsari

We present chemical abundance measurements from high resolution observations of 7 sub-damped Lyman-alpha absorbers and 1 damped Lyman-alpha system at z<1.5. Three of these objects have high metallicity, with near or super-solar Zn…

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