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Related papers: Cosmological Conductive/Cooling Fronts as Lyman Al…

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All gasdynamical models for the evolution of gaseous content of galaxies assume that cooling from the hot, virialized phase to the cold phase occured through some sort of thermal instability. Subsequent formation of colder clouds embedded…

Astrophysics · Physics 2007-05-23 Milan M. Cirkovic

We provide an analytical description of the line broadening of HI absorbers in the Lyman-alpha forest resulting from Doppler broadening and Jeans smoothing. We demonstrate that our relation captures the dependence of the line-width on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Antonella Garzilli , Tom Theuns , Joop Schaye

Recent studies have shown that galaxies accrete most of their baryons via the cold mode, from streams with temperatures T~10^4-10^5 K. At these temperatures, the streams should radiate primarily in the Lya line and have therefore been…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 C. -A. Faucher-Giguere , D. Keres , M. Dijkstra , L. Hernquist , M. Zaldarriaga

We examine the cooling radiation from forming galaxies in hydrodynamic simulations of the LCDM model (cold dark matter with a cosmological constant), focusing on the Ly-alpha line luminosities of high-redshift systems. Primordial…

We investigate the evolution of interfaces among phases of the interstellar medium with different temperature. It is found that, for some initial conditions, the dynamical effects related to conductive fronts are very important even if…

Astrophysics · Physics 2009-10-22 Andrea Ferrara , Yuri Shchekinov

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 extend a previous study of Lyman Alpha Emitters (LAEs) based on hydrodynamical cosmological simulations, by including two physical processes important for LAEs: (a) Lyman Alpha and continuum luminosities produced by cooling of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Pratika Dayal , Andrea Ferrara , Alexandro Saro

The usefulness of H I Lyman-alpha photons for characterizing star formation in the distant universe is limited by our understanding of the astrophysical processes that regulate their escape from galaxies. These processes can only be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 A. Wofford , C. Leitherer , J. Salzer

(Abridged) Despite the privileged position that Lyman-alpha (Lya) emission line holds in the exploration of the distant universe and modern observational cosmology, the origin of the observed diversity of lya profiles remains to be…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Hakim Atek , Daniel Schaerer , Daniel Kunth

The Hubble Deep Field images have provided us with a unique chance to relate statistical properties of high-redshift galaxies to statistical properties of \lya absorption systems. Combining an {\em empirical} measure of the galaxy surface…

Astrophysics · Physics 2016-08-15 Hsiao-Wen Chen , Kenneth M. Lanzetta , Alberto Fernández-Soto

We present a semi-analytical model to test the hypothesis that Ly-alpha QSO absorption lines originate in gaseous halos produced by multiple supernova explosions occurring in Pop III objects in a CDM cosmological scenario hoping to assess…

Astrophysics · Physics 2016-08-30 Benedetta Ciardi , Andrea Ferrara

The galactic evolutionary theory is now sufficiently mature to provide information about the galaxy formation phase. From evolutionary models we establish a link between the present features of late type galaxies and the protogalactic…

Astrophysics · Physics 2011-04-15 Claudio Firmani , Xavier Hernández , Vladimir Avila-Reese

At redshifts beyond z>6, as the mean fraction of neutral hydrogen x_HI in the intergalactic medium (IGM) increases, the line flux of Lyman alpha (Lya) emitters can be significantly suppressed, which can result in a decrease in the observed…

Astrophysics · Physics 2009-11-10 Zoltan Haiman , Renyue Cen

We describe cosmological simulation techniques and their application to studies of cosmic structure formation, with particular attention to recent hydrodynamic simulations of structure in the high redshift universe. Collisionless N-body…

Astrophysics · Physics 2008-02-03 David H. Weinberg , Neal Katz , Lars Hernquist

We have used STIS aboard HST to search for Lyman-alpha (Lya) absorption lines in the outer regions of eight nearby galaxies using background QSOs and AGN as probes. Lya lines are detected within a few hundred km/s of the systemic velocity…

Astrophysics · Physics 2008-11-26 David V. Bowen , Max Pettini , J. Chris Blades

A generic assumption of ionization models of quasar absorption systems is that radiation from local sources is negligible compared with the cosmological background. We test this assumption and find that it is unlikely to hold for absorbers…

Astrophysics · Physics 2009-11-10 Joop Schaye

Any viable cosmological model must produce enough structure at early epochs to explain the amount of gas associated with high-redshift damped Ly$\alpha$ systems. We study the evolution of damped Ly$\alpha$ systems at redshifts $z\ge 2$ in…

Astrophysics · Physics 2009-10-30 Chung-Pei Ma , Edmund Bertschinger , Lars Hernquist , David H. Weinberg , Neal Katz

We present a new model for high redshift Lyman-Alpha Emitters (LAEs) in the cosmological context which takes into account the resonant scattering of Ly-a photons through expanding gas. The GALICS semi-analytic model provides us with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Thibault Garel , Jérémy Blaizot , Bruno Guiderdoni , Daniel Schaerer , Anne Verhamme , Matthew Hayes

We construct a simple, robust model of the chemical evolution of galaxies from high to low redshift, and apply it to published observations of damped Lyman-alpha quasar absorption line systems (DLAs). The elementary model assumes quiescent…

Astrophysics · Physics 2009-10-31 G. P. Mathlin , A. C. Baker , D. K. Churches , M. G. Edmunds

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…