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Existing ubiquitously in the Universe with the highest luminosity, the Lyman-$\alpha$ emission line encodes abundant physical information about the gaseous medium it interacts with. Nevertheless, the resonant nature of Ly$\alpha$…

Astrophysics of Galaxies · Physics 2022-05-11 Zhihui Li , Max Gronke

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…

Astrophysics of Galaxies · Physics 2015-01-08 Simeon Bird , Martin Haehnelt , Marcel Neeleman , Shy Genel , Mark Vogelsberger , Lars Hernquist

We study the formation of damped \lya and Lyman limit absorbers in a hierarchical clustering scenario using a gas dynamical simulation of an $\Omega = 1$, cold dark matter universe. In the simulation, these high column density systems are…

Astrophysics · Physics 2009-10-28 Neal Katz , David H. Weinberg , Lars Hernquist , Jordi Miralda-Escude

We study the mean absorption spectrum of the Damped Lyman alpha population at $z\sim 2.6$ by stacking normalized, rest-frame shifted spectra of $\sim 27\,000$ DLAs from the DR12 of BOSS/SDSS-III. We measure the equivalent widths of 50…

We use our new stellar population models, which include effects from variable element abundance ratios, to model the Ca4227 absorption line indices of early-type galaxies (Trager et al.), and to derive calcium element abundances. We find…

Astrophysics · Physics 2009-11-07 Daniel Thomas , Claudia Maraston , Ralf Bender

The large crescents imaged by ALMA in transition disks suggest that azimuthal dust trapping concentrates the larger grains, but centimetre-wavelengths continuum observations are required to map the distribution of the largest observable…

We present Atacama Large Millimeter/submillimeter Array observations of the brightest cluster galaxy Hydra-A, a nearby ($z=0.054$) giant elliptical galaxy with powerful and extended radio jets. The observations reveal CO(1-0), CO(2-1),…

We present spatially-resolved properties of molecular gas and dust in a gravitationally-lensed submillimeter galaxy H-ATLAS J090311.6+003906 (SDP.81) at $z=3.042$ revealed by the Atacama Large Millimeter/submillimeter Array (ALMA). We…

Astrophysics of Galaxies · Physics 2015-08-06 Bunyo Hatsukade , Yoichi Tamura , Daisuke Iono , Yuichi Matsuda , Masao Hayashi , Masamune Oguri

Semi-analytical models of galaxy formation based on hierarchical clustering now make a wide range of predictions for observable properties of galaxies at low and high redshift. This article concentrates on 2 aspects: (1) Self-consistent…

Astrophysics · Physics 2007-05-23 Cedric Lacey , Carlton Baugh , Shaun Cole , Carlos Frenk , Fabio Governato

We study of the properties of a new class of circumgalactic medium absorbers identified in the Lyman-$\alpha$ forest: "Strong, Blended Lyman-$\alpha$" (or SBLA) absorption systems. We study SBLAs at $2.4<z<3.1$ in SDSS-IV/eBOSS spectra by…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 Sean Morrison , Debopam Som , Matthew M. Pieri , Ignasi Pérez-Ràfols , Michael Blomqvist

Cosmological parameter estimation techniques that robustly account for systematic measurement uncertainties will be crucial for the next generation of cosmological surveys. We present a new analysis method, superABC, for obtaining…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-11 Elise Jennings , Rachel Wolf , Masao Sako

Metallic thin-walled round tubes are widely used as energy absorption elements. However, lateral splash of the round tubes under impact loadings reduces the energy absorption efficiency and may cause secondary damages. Therefore, it is…

Materials Science · Physics 2016-01-20 Yuli Chen , Chuan Qiao , Shougen Zhao , Cairu Zhen , Bin Liu

We use hydrodynamic cosmological simulations to study damped Lyman-alpha (DLA) and Lyman limit (LL) absorption at redshifts z=2-4 in five variants of the cold dark matter scenario. Our standard simulations resolve the formation of dense…

Astrophysics · Physics 2016-08-31 Jeffrey P. Gardner , Neal Katz , Lars Hernquist , David H. Weinberg

The recently discovered population of ultra-faint extended line emitters can account for the majority of the incidence rate of Damped Lyman Alpha systems (DLAs) at z ~ 3 if the line emission is interpreted as Ly alpha. We show here that a…

Astrophysics · Physics 2011-01-19 Luke A. Barnes , Martin G. Haehnelt

Correctly modelling the absorptive properties of dust and haze particles is of great importance for determining the abundance of solid matter within protoplanetary disks and planetary atmospheres. Rigorous analyses such as the discrete…

Earth and Planetary Astrophysics · Physics 2024-10-30 M. G. Lodge , H. R. Wakeford , Z. M. Leinhardt

We predict and experimentally demonstrate a new type of collective (cooperative) coupling effect where a disordered atomic ensemble absorbs light with a rise-time longer (i. e., at a rate slower) than what is dictated by single-atom…

Quantum Physics · Physics 2025-11-18 D. C. Gold , U. Saglam , S. Carpenter , A. Yadav , M. Beede , T. G. Walker , M. Saffman , D. D. Yavuz

We investigate the Lyman alpha line transfer in nearby and high redshift starbursting galaxies, where the effect of high optical depths and the role of dust in the scattering medium are expected to be conspicuous and should be treated in a…

Astrophysics · Physics 2009-10-31 Sang-Hyeon Ahn , Hee-Won Lee , Hyung Mok Lee

We investigate the metal enrichment of elliptical galaxies in the framework of hierarchical models of galaxy formation. The semi-analytical model we use in this Letter, which has been used to study the metal enrichment of the intracluster…

We derive semi-analytic solutions for the thermally driven cumulative outflow from a dense stellar cluster that consists of a large number of stars with strong stellar winds, under the key assumption that their mass and energy deposition…

Solar and Stellar Astrophysics · Physics 2025-07-28 Stan Owocki

We present Giant Metrewave Radio Telescope HI 21cm absorption observations, of candidate and confirmed damped Lyman-$\alpha$ systems (DLAS). The derived spin temperatures (T_s) are in all cases $\sim 1000$ K or higher. We have also collated…

Astrophysics · Physics 2015-06-24 Jayaram N Chengalur , Nissim Kanekar