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Damped Ly$\alpha$ systems provide possibly the most significant evidence for early structure formation, and thus a stringent constraint on the Cold + Hot Dark Matter (CHDM) cosmology. Using the numbers of halos in N-body simulations to…

Astrophysics · Physics 2009-09-25 Anatoly Klypin , Stefano Borgani , Jon Holtzman , Joel Primack

We present the chemical abundance measurements of the first large, medium-resolution, uniformly selected damped Lyman alpha system (DLA) survey. The sample contains 99 DLAs towards 89 quasars selected from the SDSS DR5 DLA sample in a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Regina A. Jorgenson , Michael T. Murphy , Rodger Thompson

We present a large sample of Ly-alpha emitting galaxies spectroscopically confirmed at z~4.5, based on IMACS spectroscopic observations of candidate LAEs in the LALA Cetus field. We identify 110 z~4.5 LAEs based on single line detections…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Jun-Xian Wang , Sangeeta Malhotra , James E. Rhoads , Hao-Tong Zhang , Steven L. Finkelstein

We report on a sensitive search for redshifted H$\alpha$ line-emission from three high-metallicity damped Ly$\alpha$ absorbers (DLAs) at $z \approx 2.4$ with the Near-infrared Integral Field Spectrometer (NIFS) on the Gemini-North…

Astrophysics of Galaxies · Physics 2015-06-23 Wei-Hao Wang , Nissim Kanekar , J. Xavier Prochaska

Given the failure of existing models for redshift-space distortions to provide a highly accurate measure of the beta-parameter, and the ability of forthcoming surveys to obtain data with very low random errors, it becomes necessary to…

Astrophysics · Physics 2009-10-31 S. J. Hatton , S. Cole

Aims. Ly-alpha emitters (LAEs) can be detected out to very high redshifts during the epoch of reionization. The evolution of the LAE luminosity function with redshift is a direct probe of the Ly-alpha transmission of the intergalactic…

We provide a comparative study of the fine tuning amount (Delta) at the two-loop leading log level in supersymmetric models commonly used in SUSY searches at the LHC. These are the constrained MSSM (CMSSM), non-universal Higgs masses models…

High Energy Physics - Phenomenology · Physics 2015-06-04 D. M. Ghilencea , H. M. Lee , M. Park

We used our database of ESO VLT-UVES spectra of quasars to build up a sample of 67 Damped Lyman-alpha (DLA) systems with redshifts 1.7<zabs<3.7. For each system, we measured average metallicities relative to Solar, [X/H] (with either X=Zn,…

Astrophysics · Physics 2009-11-11 C. Ledoux , P. Petitjean , P. Moller , J. Fynbo , R. Srianand

Although the Cold + Hot Dark Matter (CHDM) cosmology provides perhaps the best fit of any model to all the available data at the current epoch, CHDM produces structure at relatively low redshifts and thus could be ruled out if there were…

Astrophysics · Physics 2009-10-22 Anatoly Klypin , Stefano Borgani , Jon Holtzman , Joel Primack

We estimate the intrinsic neutral gas density in Damped Lyman Alpha systems ($\Omega_{HI}^{(DLA)}$) in the redshift range $ 2.2 \lesssim z \lesssim 5$ from the DLA SDSS DR_3 sample of optically selected quasars. We take into account…

Astrophysics · Physics 2008-11-26 M. Trenti , M. Stiavelli

We present constraints on the spacetime variation of the fine-structure constant $\alpha$ at redshifts $2.5\le z<9.5$ using JWST emission-line galaxies. The galaxy sample consists of 621 high-quality spectra with strong and narrow [O III]…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Linhua Jiang , Shuqi Fu , Feige Wang , Sarah E. I. Bosman , Zheng Cai , Hyunsung D. Jun , Zhiwei Pan , Fengwu Sun , Jinyi Yang , Huanian Zhang

We examine the nature of galaxy clustering in redshift space using a method based on an expansion of the galaxian density field in Spherical Harmonics and linear theory. We derive a compact and self-consistent expression for the distortion…

Astrophysics · Physics 2007-05-23 Karl B. Fisher

Lyman-$\alpha$ forest data are known to be a good probe of the small scale matter power. In this paper, we explore the redshift evolution of the observable effective optical depth $\tau_{\rm eff} (z)$ from the Lyman-$\alpha$ data as a…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-03 Anjan Kumar Sarkar , Kanhaiya L. Pandey , Shiv K. Sethi

We present the measured gas-phase metal column densities in 155 sub-damped Lyman alpha systems (subDLAs) with the aim to investigate the contribution of subDLAs to the chemical evolution of the Universe. The sample was identified within the…

The red-shift space distortions in the galaxy power spectrum can be used to measure the growth rate of matter density perturbations delta_m. For dynamical dark energy models in General Relativity we provide a convenient analytic formula of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Shinji Tsujikawa , Antonio De Felice , Jailson Alcaniz

We explore how to mitigate the clustering distortions in Lyman-$\alpha$ emitters (LAEs) samples caused by the miss-identification of the Lyman-$\alpha$ (Ly$\alpha$) wavelength in their Ly$\alpha$ line profiles. We use the Ly$\alpha$ line…

Astrophysics of Galaxies · Physics 2020-10-28 Siddhartha Gurung-Lopez , Shun Saito , Carlton M. Baugh , Silvia Bonoli , Cedric G. Lacey , Alvaro A. Orsi

We present the results from the optical component of a survey for damped Lyman-alpha systems (DLAs) towards radio-loud quasars. Our quasar sample is drawn from the Texas radio survey with the following primary selection criteria: z_em >…

Astrophysics · Physics 2009-11-13 Sara L. Ellison , Brian A. York , Max Pettini , Nissim Kanekar

Rest-frame UV spectral lines of star-forming galaxies are systematically offset from the galaxies' systemic redshifts, probably because of large-scale outflows. We calibrate galaxy redshifts measured from rest-frame UV lines by utilizing…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Olivera Rakic , Joop Schaye , Charles C. Steidel , Gwen C. Rudie

We present results from an efficient, non-traditional survey to discover damped Lyman-alpha (DLA) absorption-line systems with neutral hydrogen column densities N(HI)>2x10^{20} atoms cm^{-2} and redshifts z<1.65. Contrary to previous…

Astrophysics · Physics 2007-05-23 Sandhya Rao

An accurate method to measure the abundance of high-redshift galaxies consists in the observation of absorbers along the line of sight toward a background quasar. Here, we present abundance measurements of 13 z>3 sub-Damped Lyman-alpha…