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Related papers: Intensity mapping with neutral hydrogen and the Hi…

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We study the structure and evolution of dark matter halos from z = 300 to z = 6 for two cosmological N-body simulation initialization techniques. While the second order Lagrangian perturbation theory (2LPT) and the Zel'dovich approximation…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-17 Daniel J. Sissom , Kelly Holley-Bockelmann , Manodeep Sinha

We present the measurements and modelling of the small-to-intermediate scale (0.1--25 Mpc/h) projected and three-dimensional (3D) redshift-space two-point correlation functions (2PCFs) of local galaxies in the Sloan Digital Sky Survey…

The epoch of reionization is one of the least known chapters in the evolutionary history of the Universe. This thesis investigates two major approaches to unveil the reionization history of the Universe using HI 21-cm maps.The most…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-04 Kanan K. Datta

We characterize the baryon acoustic oscillations (BAO) feature in halo two-point statistics using N-body simulations. We find that nonlinear damping of the BAO signal is less severe for halos in the mass range we investigate than for dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Qiao Wang , Hu Zhan

It was recently shown that the power spectrum in redshift space can be written as a sum of cross-power spectra between number weighted velocity moments. We investigate the properties of these power spectra for simulated galaxies and dark…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Teppei Okumura , Uros Seljak , Vincent Desjacques

Gravitational redshifts and other relativistic effects are beginning to be studied in the context of galaxy clustering. Distortions consistent with those expected in General Relativity have been measured in galaxy cluster redshift profiles…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-18 Hongyu Zhu , Shadab Alam , Rupert A. C. Croft , Shirley Ho , Elena Giusarma

Arecibo mapping is reported of the neutral hydrogen distribution along selected directions out from the centers of two small High Velocity Clouds (HVC), W486 and W491. Both HVCs have a small inner region where the neutral hydrogen column…

Astrophysics · Physics 2009-11-07 G. L. Hoffman , E. E. Salpeter , M. G. Pocceschi

We give a summary of recent results on spatial and velocity biases in cosmological models. Progress in numerical techniques made it possible to simulate halos in large volumes with a such accuracy that halos survive in dense environments of…

Astrophysics · Physics 2007-05-23 Anatoly Klypin

The 21-cm intensity mapping (IM) of neutral hydrogen (HI) is a promising tool to probe the large-scale structures. Sky maps of 21-cm intensities can be highly contaminated by different foregrounds, such as Galactic synchrotron radiation,…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-01 Elimboto Yohana , Yin-Zhe Ma , Di Li , Xuelei Chen , Wei-Ming Dai

We use the Gigaparsec WiggleZ (GiggleZ) simulations to characterise galaxy bias and its scale dependence for a range of redshifts and halo masses in a standard $\Lambda$LCDM cosmology. Assuming bias converges to a scale independent form at…

We use the Galaxies-Intergalactic Medium Interaction Calculation (GIMIC) cosmological hydrodynamic simulation at z=0 to study the distribution and environmental dependence of neutral hydrogen (HI) gas in the outskirts of simulated galaxies.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 D. Cunnama , S. Andrianomena , C. M. Cress , A. Faltenbacher , B. K. Gibson , T. Theuns

A new and promising technique for observing the Universe and study the dark sector is the intensity mapping of the redshifted 21cm line of neutral hydrogen (HI). The BINGO radio telescope will use the 21cm line to map the Universe in the…

We present the largest homogeneous survey of $z>4.4$ damped Lyman-$\alpha$ systems (DLAs) using the spectra of 163 QSOs that comprise the Giant Gemini GMOS (GGG) survey. With this survey we make the most precise high-redshift measurement of…

Dark matter N-body simulations provide a powerful tool to model the clustering of galaxies and help interpret the results of galaxy redshift surveys. However, the galaxy properties predicted from N-body simulations are not necessarily…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-30 Hao-Yi Wu , Dragan Huterer

Aims: We measure the clustering properties for a large samples of u- (z~3), g- (z~4), and r- (z~5) dropouts from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) Deep fields. Methods: Photometric redshift distributions along with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 H. Hildebrandt , J. Pielorz , T. Erben , L. van Waerbeke , P. Simon , P. Capak

We explore the information content of 21cm intensity maps in redshift space using the 1-loop Effective Field Theory power spectrum model and the bispectrum at tree level. The 21cm signal contains signatures of dark matter, dark energy and…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 Liantsoa F. Randrianjanahary , Dionysios Karagiannis , Roy Maartens

We study the intrinsic shape and alignment of isodensities of galaxy cluster halos extracted from the MultiDark MDR1 cosmological simulation. We find that the simulated halos, are extremely prolate on small scales, and increasingly…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 A. M. Groener , D. M. Goldberg

Hydrogen atoms inside virialized minihalos generate a radiation background from redshifted 21-cm line emission whose angular fluctuations reflect clustering during before and during reionization. We have shown elsewhere that this emission…

Astrophysics · Physics 2007-05-23 Ilian T. Iliev , Evan Scannapieco , Hugo Martel , Paul R. Shapiro

The H atoms inside minihalos (i.e. halos with virial temperatures T_vir < 10^4 K, in the mass range roughly from 10^4 M_sun to 10^8 M_sun) during the cosmic dark ages in a LambdaCDM universe produce a redshifted background of…

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