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Related papers: On the Small-Scale Clustering of Ly-alpha Forest C…

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We present the first measurement of the large-scale cross-correlation of Lyman alpha forest absorption and Damped Lyman alpha systems (DLA), using the 9th Data Release of the Baryon Oscillation Spectroscopic Survey (BOSS). The…

We calculate the column density distribution of damped Lyman alpha systems, modeled as spherical isothermal gaseous halos ionized by the external cosmic background. The effects of self-shielding introduce a hump in this distribution, at a…

Astrophysics · Physics 2009-11-07 Zheng Zheng , Jordi Miralda-Escude

We use state of the art hydrodyamical simulations from the Sherwood, EAGLE and Illustris projects to examine the signature of $M_{\rm z=0}\simeq 10^{14}M_{\odot}$ protoclusters observed in Ly-$\alpha$ absorption at $z\simeq 2.4$. We find…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-13 Joel S. A. Miller , James S. Bolton , Nina Hatch

Using the Ly$\alpha$ mass assignment scheme (LyMAS), we make theoretical predictions for the 3-dimensional 3-point correlation function (3PCF) of the Ly$\alpha$ forest at redshift $z=2.3$. We bootstrap results from the (100 $h^{-1} \mbox{…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Suk Sien Tie , David H. Weinberg , Paul Martini , Wei Zhu , Sebastien Peirani , Teresita Suarez , Stephane Colombi

Clustering is a fundamental task in unsupervised learning. The focus of this paper is the Correlation Clustering functional which combines positive and negative affinities between the data points. The contribution of this paper is two fold:…

Computer Vision and Pattern Recognition · Computer Science 2011-12-14 Shai Bagon , Meirav Galun

We review the arguments for how the slope of the column density distribution of the Lyman-alpha forest should depend on the matter power spectrum. The latest progress, presented by various groups in this conference and elsewhere, is…

Astrophysics · Physics 2007-05-23 Lam Hui

The galaxy correlation function serves as a fundamental tool for studying cosmology, galaxy formation, and the nature of dark matter. It is well established that more massive, redder and more compact galaxies tend to have stronger…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-27 Ziwen Zhang , Yangyao Chen , Yu Rong , Huiyuan Wang , Houjun Mo , Xiong Luo , Hao Li

We develop an analytical method based on the lognormal approximation to compute the column density distribution of the Lyman-alpha forest in the low column density limit. We compute the column density distributions for six different…

Astrophysics · Physics 2009-10-28 Nickolay Y. Gnedin , Lam Hui

(abridged) We present a study of the angular correlation function as measured in the William Herschel Deep Field. This field covers 50 arcmin$^2$ and with it we are able to investigate the scaling of the angular correlation function to…

Astrophysics · Physics 2009-10-31 H. J. McCracken , T. Shanks , N. Metcalfe , R. Fong , A. Campos

We present a model for the Lyman-alpha absorbers that treats all objects (from the low-density forest clouds to the dense damped systems) in a unified description. This approach is consistent with an earlier model of galaxies (luminosity…

Astrophysics · Physics 2007-05-23 P. Valageas , R. Schaeffer , J. Silk

We present a physically motivated semi-analytic model to understand the clustering of high redshift Lyman Alpha Emitters (LAEs). We show that the model parameters constrained by the observed luminosity functions, can be used to predict…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Charles Jose , Raghunathan Srianand , Kandaswamy Subramanian

The steady state of the model of cluster aggregation with deposition is characterized by a constant flux of mass directed from small masses towards large masses. It can therefore be studied using phenomenological theories of turbulence,…

Statistical Mechanics · Physics 2009-11-10 Colm Connaughton , R. Rajesh , Oleg Zaboronski

We apply the time-dependent local density approximation (TDLDA) to calculate dipole excitations in small carbon clusters. A strong low-frequency mode is found which agrees well with observation for clusters C_n with n in the range 7-15. The…

Chemical Physics · Physics 2009-10-30 K. Yabana , G. F. Bertsch

Observations of the Lyman-$\alpha$ (Ly$\alpha$) forest from spectroscopic surveys such as BOSS/eBOSS, or the ongoing DESI, offer a unique window to study the growth of structure on megaparsec scales. Interpretation of these measurements is…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-09 Christian Pedersen , Andreu Font-Ribera , Nickolay Y. Gnedin

Lyman-alpha forest lines in QSO spectra have typical widths of 20-50 km/s. Low column density absorbers in cosmological simulations are large, diffuse structures, and the Hubble flow across the spatially extended absorber is usually the…

Astrophysics · Physics 2007-05-23 David H. Weinberg , Lars Hernquist , Neal Katz , Rupert Croft , Jordi Miralda-Escudé

We have obtained spectroscopy of Q 1343+266 AB, a pair of quasars at redshift z = 2.03 with a projected separation of 9.5 arcseconds. This system is well-suited for probing the Ly-alpha forest, since the two component spectra show several…

Astrophysics · Physics 2009-10-22 Jill Bechtold , Arlin P. S. Crotts , Robert C. Duncan , Yihu Fang

We investigate the nonlinear two- and three-point correlation functions of the cosmological density field in Fourier space and test the popular hierarchical clustering model, that the three-point amplitude Q is independent of scale. In…

Astrophysics · Physics 2009-10-31 Chung-Pei Ma , J. N. Fry

In this paper, we present results of extensive Monte Carlo simulations of diffusion-limited aggregation (DLA) with a seed placed on an attractive plane as a simple model in connection with the electrical double layers. We compute the…

Statistical Mechanics · Physics 2012-07-31 S. H. Ebrahimnazhad Rahbari , A. A. Saberi

The comparison of quasar absorption spectra with numerically simulated spectra from hierarchical cosmological models of structure formation promises to be a valuable tool to discriminate among these models. We present simulation results for…

Astrophysics · Physics 2009-10-31 M. Machacek , G. Bryan , P. Anninos , A. Meiksin , M. L. Norman , Y. Zhang
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