scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: large-scale structure catalogues and measurement of the isotropic BAO between redshift 0.6 and 1.1 for the Emission Line Galaxy Sample

2020 ◽  
Vol 500 (3) ◽  
pp. 3254-3274
Author(s):  
Anand Raichoor ◽  
Arnaud de Mattia ◽  
Ashley J Ross ◽  
Cheng Zhao ◽  
Shadab Alam ◽  
...  
Keyword(s):  
Emission Line ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Sloan Digital Sky Survey ◽  
Acoustic Oscillations ◽  
Galaxy Sample ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Line Galaxy

ABSTRACT We present the Emission Line Galaxy (ELG) sample of the extended Baryon Oscillation Spectroscopic Survey from the Sloan Digital Sky Survey IV Data Release 16. We describe the observations and redshift measurement for the 269 243 observed ELG spectra, and then present the large-scale structure catalogues, used for the cosmological analysis, and made of 173 736 reliable spectroscopic redshifts between 0.6 and 1.1. We perform a spherically averaged baryon acoustic oscillations (BAO) measurement in configuration space, with density field reconstruction: the data two-point correlation function shows a feature consistent with that of the BAO, the BAO model being only weakly preferred over a model without BAO (Δχ2 < 1). Fitting a model constrained to have a BAO feature provides a 3.2 per cent measurement of the spherically averaged BAO distance DV(zeff)/rdrag = 18.23 ± 0.58 at the effective redshift zeff = 0.845.

The Local Large-Scale Structure from HIPASS

2005 ◽  
Vol 216 ◽  
pp. 196-202
Author(s):  
Martin Zwaan ◽  
Martin Meyer ◽  
Rachel Webster ◽  
Lister Staveley-Smith
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Sky Survey ◽  
The Galaxy ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Fisher Relation ◽  
Galaxy Population ◽  
Mass Functions

The HI Parkes All Sky Survey (HIPASS) offers a unique perspective on the galaxy population in the local universe. A catalogue of 4315 HI-selected galaxies has been extracted from the southern region of the survey (δ < +2°). This catalogue gives a clear view of the local large-scale structure and is used to study the two-point correlation function, the Tully-Fisher relation, and galaxy luminosity and mass functions. Some initial results are discussed here.

CHAOTIC INFLATIONARY UNIVERSE AND THE ANISOTROPY OF THE LARGE-SCALE STRUCTURE

1990 ◽  
Vol 05 (13) ◽  
pp. 2625-2646 ◽  
Author(s):  
G. V. CHIBISOV ◽  
YU. V. SHTANOV
Keyword(s):  
Correlation Function ◽  
Large Scale ◽  
Large Scale Structure ◽  
Expected Value ◽  
Scale Structure ◽  
Inflationary Universe ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Inflation Scenario ◽  
Chaotic Inflation

In frames of the chaotic inflation scenario the influence of the inhomogeneity of the inflationary universe on the primordial fluctuations spectrum is investigated. The phenomenon of the anisotropy of the observed large-scale structure is predicted. In particular this means that the two-point correlation function ξ(x) is anisotropic. An expected value of the anisotropy is about 10%. The observation of the anisotropy predicted could serve as confirmation to the chaotic inflation scenario.

scholarly journals N-Body Simulation of Large Scale Structure in the Universe with Oscillating Scalar Field

1999 ◽  
Vol 183 ◽  
pp. 252-252
Author(s):  
K. Kawabata ◽  
H. Taguchi ◽  
Y. Andoh
Keyword(s):  
Scalar Field ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Homogeneous Distribution ◽  
Coupling Constant ◽  
Mesh Method ◽  
Point Correlation ◽  
Point Correlation Function ◽  
The Universe

Using the particle-mesh method with 1283 grids and 643 particles, we have carried out a number of N-body simulations of the large scale structure for the cosmological model proposed by Fukuyama et al.(1996): this model contains the matter(Ω0) as well as a scalar field(Φ) with a finite mass that couples non-minimally with the scalar curvature R through the form of 1/2ηΦ2R, where η(= −80) is the coupling constant.For simplicity, we have adopted the same values as those employed by Fukuyama et al.(1996) for all the parameters other than Ω0, fo which we have varied from 0.001 to 0.15. In performing our simulation, we further assume that only the density of matter ρ spatially fluctuates. The initial condition is created by perturbing the homogeneous distribution of the particles by means of the random Gaussian Harrison-Zeldovich spectrum.The two-point correlation function ξ(r) is then compputed for each of the resulting structures to compare with the observational data(Davis and Peebles, 1983). It is interesting to note that the structure formation appears to be achieved rather straightforwardly with the scalar field model. However, in order to yield an agreement between the theoretical and the observational two-point correlation functions, we seem to require the Ω0 value much larger than 0.01 adopted by Fukuyama et al.(1996).

scholarly journals The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: GLAM-QPM mock galaxy catalogues for the emission line galaxy sample

2020 ◽  
Vol 498 (4) ◽  
pp. 5251-5262 ◽  
Author(s):  
Sicheng Lin ◽  
Jeremy L Tinker ◽  
Anatoly Klypin ◽  
Francisco Prada ◽  
Michael R Blanton ◽  
...  
Keyword(s):  
Emission Line ◽  
Large Scale ◽  
Small Scale ◽  
Selection Function ◽  
Number Density ◽  
Acoustic Oscillations ◽  
Systematic Analysis ◽  
Galaxy Sample ◽  
Halo Occupation Distribution ◽  
Line Galaxy

ABSTRACT We present 2000 mock galaxy catalogues for the analysis of baryon acoustic oscillations (BAOs) in the Emission Line Galaxy (ELG) sample of the extended Baryon Oscillation Spectroscopic Survey Data Release 16 (eBOSS DR16). Each mock catalogue has a number density of $6.7 \times 10^{-4} h^3 \rm Mpc^{-3}$, covering a redshift range from 0.6 to 1.1. The mocks are calibrated to small-scale eBOSS ELG clustering measurements at scales of $\lesssim 30\, h^{-1}$Mpc. The mock catalogues are generated using a combination of GaLAxy Mocks (GLAM) simulations and the quick particle-mesh (QPM) method. GLAM simulations are used to generate the density field, which is then assigned dark matter haloes using the QPM method. Haloes are populated with galaxies using a halo occupation distribution. The resulting mocks match the survey geometry and selection function of the data, and have slightly higher number density that allows room for systematic analysis. The large-scale clustering of mocks at the BAO scale is consistent with data and we present the correlation matrix of the mocks.

scholarly journals Large-Scale Structure in the Durham/Ukst Galaxy Redshift Survey

1994 ◽  
Vol 161 ◽  
pp. 693-697
Author(s):  
A. Broadbent ◽  
T. Shanks ◽  
F.G. Watson ◽  
Q.A. Parker ◽  
R. Fong ◽  
...  
Keyword(s):  
Correlation Function ◽  
Statistical Analysis ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey ◽  
Galaxy Redshift ◽  
The Universe

We report on the progress of the compilation and analysis of the Durham/UKST galaxy redshift survey. This survey will probe a large contiguous volume of space within a 1500 sq. deg. area of sky around the SGP. It will contain redshifts of ∼ 4000 galaxies of bJ &lt; 17m providing detailed information about the structure of the Universe on large scales. Large features on scales of ∼ 100h−1 Mpc are clearly visible on examination of the completed section of the survey, although a statistical analysis of the survey by means of the two-point correlation function is close to zero on scales of r &gt; 10h−1 Mpc.

scholarly journals The effect of large-scale structure on the SDSS galaxy three-point correlation function

2006 ◽  
Vol 368 (4) ◽  
pp. 1507-1514 ◽  
Author(s):  
R. C. Nichol ◽  
R. K. Sheth ◽  
Y. Suto ◽  
A. J. Gray ◽  
I. Kayo ◽  
...  
Keyword(s):  
Correlation Function ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Point Correlation ◽  
Point Correlation Function

scholarly journals Using Unreal Engine to Visualize a Cosmological Volume

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 168
Author(s):  
Christopher Marsden ◽  
Francesco Shankar
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Graphics Processing Unit ◽  
Large Scale Structure ◽  
Two Dimensions ◽  
Scale Structure ◽  
Sloan Digital Sky Survey ◽  
Processing Unit ◽  
Large Scale Universe ◽  
Time Projection

In this work we present “Astera’’, a cosmological visualization tool that renders a mock universe in real time using Unreal Engine 4. The large scale structure of the cosmic web is hard to visualize in two dimensions, and a 3D real time projection of this distribution allows for an unprecedented view of the large scale universe, with visually accurate galaxies placed in a dynamic 3D world. The underlying data are based on empirical relations assigned using results from N-Body dark matter simulations, and are matched to galaxies with similar morphologies and sizes, images of which are extracted from the Sloan Digital Sky Survey. Within Unreal Engine 4, galaxy images are transformed into textures and dynamic materials (with appropriate transparency) that are applied to static mesh objects with appropriate sizes and locations. To ensure excellent performance, these static meshes are “instanced’’ to utilize the full capabilities of a graphics processing unit. Additional components include a dynamic system for representing accelerated-time active galactic nuclei. The end result is a visually realistic large scale universe that can be explored by a user in real time, with accurate large scale structure. Astera is not yet ready for public release, but we are exploring options to make different versions of the code available for both research and outreach applications.

scholarly journals Large Scale Structure of the Universe

1998 ◽  
Vol 179 ◽  
pp. 317-328 ◽  
Author(s):  
N.A. Bahcall
Keyword(s):  
Large Scale ◽  
Initial Conditions ◽  
Large Scale Structure ◽  
Density Fluctuations ◽  
Scale Structure ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Initial Spectrum ◽  
Formation And Evolution ◽  
The Universe

How is the universe organized on large scales? How did this structure evolve from the unknown initial conditions of a rather smooth early universe to the present time? The answers to these questions will shed light on the cosmology we live in, the amount, composition and distribution of matter in the universe, the initial spectrum of density fluctuations that gave rise to this structure, and the formation and evolution of galaxies, lusters of galaxies, and larger scale structures.To address these fundamental questions, large and accurate sky surveys are needed—in various wavelengths and to various depths. In this presentation I review current observational studies of large scale structure, present the constraints these observations place on cosmological models and on the amount of dark matter in the universe, and highlight some of the main unsolved problems in the field of large-scale structure that could be solved over the next decade with the aid of current and future surveys. I briefly discuss some of these surveys, including the Sloan Digital Sky Survey that will provide a complete imaging and spectroscopic survey of the high-latitude northern sky, with redshifts for the brightest ∼ 106 galaxies, 105 quasars, and 103.5 rich clusters of galaxies. The potentialities of the SDSS survey, as well as of cross-wavelength surveys, for resolving some of the unsolved problems in large-scale structure and cosmology are discussed.

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