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Related papers: Lyman Alpha Forest towards B2 1225+317

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We report the serendipitous discovery of two objects close in projection with fairly strong emission lines at long wavelength (~9190 A). One (A) seems not to be hosted by any galaxy brighter than V(555)=27.5, or I(814)=26.7 (Vega-based…

Astrophysics · Physics 2009-10-31 Daniel Stern , Andrew J. Bunker , Hyron Spinrad , Arjun Dey

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

We analyze Ly-alpha fluoresced H2 lines observed in the UV spectrum of Mira B. We identify 13 different sequences fluoresced by 13 different H2 transitions within the Ly-alpha line. The observed H2 line ratios within these sequences imply…

Astrophysics · Physics 2009-11-07 Brian E. Wood , Margarita Karovska , John C. Raymond

Using a Monte Carlo technique, we have developed a 3D lyman-alpha radiation transfer code allowing for prescribed arbitrary hydrogen density, ionisation, temperature structures, and dust distribution, and arbitrary velocity fields and UV…

Astrophysics · Physics 2009-11-11 Anne Verhamme , Daniel Schaerer , Antonella Maselli

We examine the statistics of the low-redshift Lyman-alpha forest from smoothed particle hydrodynamic simulations in light of recent improvements in the estimated evolution of the cosmic ultraviolet background (UVB) and recent observations…

In this paper we review the importance of the Lyman alpha forest as a probe of structure formation in the universe. We first discuss the statistics used to describe the Lyman alpha forest and the numerical techniques used to produce…

Astrophysics · Physics 2007-05-23 Marie E. Machacek , Greg L. Bryan , Peter Anninos , Avery Meiksin , Michael L. Norman

We use hydrodynamic simulations to predict correlations between Lya forest absorption and galaxies at redshift z~3. The probability distribution function (PDF) of Lya flux decrements shifts systematically towards higher values in the…

Astrophysics · Physics 2009-11-07 Juna A. Kollmeier , David H. Weinberg , Romeel Dave' , Neal Katz

This paper describes a study of the Lyman-alpha forest absorption clouds along the quasar sightline Q0000-26 (zem=4.1). The spectrum was obtained with the High Resolution Spectrometer on the 10m Keck telescope. We derive accurate H I column…

Astrophysics · Physics 2009-10-28 Limin Lu , Wallace L. W. Sargent , Donna S. Womble , Masahide Takada-Hidai

Using STIS and VLT UVES observations we have examined the ionization, abundances, and differential dust depletion of metals, the kinematic structure, and the physical conditions in the molecular hydrogen-bearing sub-damped Ly alpha system…

Astrophysics · Physics 2009-11-13 R. Quast , D. Reimers , R. Baade

We measure the effect of high column density absorbing systems of neutral hydrogen (HI) on the one-dimensional (1D) Lyman-alpha forest flux power spectrum using cosmological hydrodynamical simulations from the Illustris project. High column…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-10 Keir K. Rogers , Simeon Bird , Hiranya V. Peiris , Andrew Pontzen , Andreu Font-Ribera , Boris Leistedt

A simple consistency argument for hypothesis of the galactic halo origin of the Ly-alpha forest absorption lines is advanced, based on the recent determination of column-density vs. impact parameter relation for the low-redshift gaseous…

Astrophysics · Physics 2015-06-24 Milan M. Cirkovic , Srdjan Samurovic

We analyze the SDSS Ly-alpha forest P_F(k,z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-PM simulations. We account for the effect of absorbers…

We present the clustering properties of 151 Lyman alpha emitting galaxies at z ~ 4.5 selected from the Large Area Lyman Alpha (LALA) survey. Our catalog covers an area of 36' x 36' observed with five narrowband filters. We assume that the…

We present a study of the spatial coherence of the intergalactic medium toward two pairs of high-redshift quasars with moderate angular separations observed with Keck/ESI, Q1422+2309A/Q1424+2255 (z_em = 3.63, theta = 39") and Q1439-0034A/B…

Astrophysics · Physics 2009-11-10 George D. Becker , Wallace L. W. Sargent , Michael Rauch

We present 40 fully hydrodynamical numerical simulations of the intergalactic gas that gives rise to the Ly-alpha forest. We make artificial spectra from each and measure three output parameters: the mean flux, a measure of the most common…

The Lyman-alpha emission line is the strongest feature in the spectrum of most high redshift galaxies, and is typically observed as being highly asymmetric due to galactic outflows. Quantifying this asymmetry is challenging. Here, we…

Astrophysics of Galaxies · Physics 2018-08-08 Henry J. T. Childs , Elizabeth R. Stanway

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

Lyman-$\alpha$(Ly$\alpha$) forest in the spectra of distant quasars encodes the information of the underlying cosmic density field at smallest scales. The modelling of the upcoming large and high-fidelity forest data using cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-10 Bhaskar Arya

We show in this paper why molecular millimeter absorption line searches in DLAs have been unsuccessful. We use CO emission line maps of local galaxies to derive the H2 column density distribution function f(N_H2) at z=0. We show that it…

Astrophysics · Physics 2009-11-11 M. A. Zwaan , J. X. Prochaska

The analysis of the Lyman-alpha forest of absorption lines in quasar spectra has emerged as a potentially powerful technique to constrain the linear matter power spectrum. In most previous work, the amplitude of the ionizing background was…

Astrophysics · Physics 2009-11-11 Adam Lidz , Katrin Heitmann , Lam Hui , Salman Habib , Michael Rauch , Wallace L. W. Sargent
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