The Galaxy Distribution and the Large-Scale Structure of the Universe

1986 ◽  
Vol 470 (1 Twelfth Texas) ◽  
pp. 123-135
Author(s):  
MARGARET J. GELLER ◽  
VALÉRIE LAPPARENT ◽  
MICHAEL J. KURTZ
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
The Universe

scholarly journals Mapping the Large-Scale Structure

1994 ◽  
Vol 161 ◽  
pp. 669-686
Author(s):  
V. de Lapparent
Keyword(s):  
Large Scale ◽  
Background Radiation ◽  
Theoretical Models ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Nearby Galaxy ◽  
Redshift Surveys ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
Microwave Background Radiation

The nearby galaxy distribution suggests a remarkable structure in which large voids are delineated by dense walls of galaxies in a cell-like pattern. The nearby voids range in diameter from ∼ 10 to ∼ 50h− 1 Mpc. Deeper surveys appear to be consistent with the nearby distribution and show no evidence of voids larger than ∼ 100h −1 ∗ Mpc. We might thus have reached the scale where the universe becomes homogeneous. The size of the largest inhomogeneities in the galaxy distribution is an important issue because it can put tight constraints on the theoretical models when confronted by the high degree of isotropy of the microwave background radiation. Comparison of the various existing redshift surveys emphasizes the need for systematic redshift surveys over significant areas of the sky out to intermediate and large distances. Although deep pencil-beam surveys are best suited for probing a large number of voids and walls, understanding the nature of the intercepted peaks and valleys in terms of large-scale structure requires that the angular coverage of the surveys be larger than the galaxy auto-correlation length. If this condition is not satisfied, the size of the voids and the density contrast of the walls can be overestimated.

scholarly journals Tracing Large-Scale Structure with Galaxy Objective-Prism Spectra

1988 ◽  
Vol 130 ◽  
pp. 525-525
Author(s):  
Q.A. Parker ◽  
H.T. Macgillivray ◽  
S.M. Beard
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Early Type ◽  
Galaxy Distribution ◽  
Large Numbers ◽  
The Galaxy ◽  
Measured Sample ◽  
Objective Prism ◽  
Low Dispersion

A new and promising use of galaxy objective-prism spectra as a means of highlighting features in the large scale galaxy distribution has been recently reported by Parker et al. (1987). The technique relies on the property that galaxies with identifiable 4000Å features in low dispersion objective-prism spectra are mostly ellipticals (Cooke, 1980), and that early type galaxies seem to delineate structure and clumpiness in the galaxy distribution (e.g. Giovanelli and Haynes, 1982). The effect is most striking when large numbers of objective-prism galaxy spectra are considered. Figure 1 gives the X-Y plot for 1539 galaxies with 4000Å features to Bj=18.7 in one UKST field out of a manually measured sample of 2903 galaxy prism spectra. Substantial clumpiness is evident. This technique can trace structure in the galaxy distribution across many UKST fields to depths of 400 h−1Mpc.

scholarly journals The relation between Lyα absorbers and local galaxy filaments

2021 ◽  
Vol 647 ◽  
pp. A166
Author(s):  
S. J. D. Bouma ◽  
P. Richter ◽  
M. Wendt
Keyword(s):  
Large Scale ◽  
High Redshift ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Density Distribution Function ◽  
Exact Relation ◽  
The Galaxy ◽  
Kolmogorov Smirnov ◽  
The Universe ◽  
Smirnov Test

Context. The intergalactic medium (IGM) is believed to contain the majority of baryons in the universe and to trace the same dark matter structure as galaxies, forming filaments and sheets. Lyα absorbers, which sample the neutral component of the IGM, have been extensively studied at low and high redshift, but the exact relation between Lyα absorption, galaxies, and the large-scale structure is observationally not well constrained. Aims. In this study, we aim at characterising the relation between Lyα absorbers and nearby over-dense cosmological structures (galaxy filaments) at recession velocities Δv ≤ 6700 km s−1 by using archival observational data from various instruments. Methods. We analyse 587 intervening Lyα absorbers in the spectra of 302 extragalactic background sources obtained with the Cosmic Origins Spectrograph (COS) installed on the Hubble Space Telescope (HST). We combine the absorption line information with galaxy data of five local galaxy filaments from the V8k catalogue. Results. Along the 91 sightlines that pass close to a filament, we identify 215 (227) Lyα absorption systems (components). Among these, 74 Lyα systems are aligned in position and velocity with the galaxy filaments, indicating that these absorbers and the galaxies trace the same large-scale structure. The filament-aligned Lyα absorbers have a ∼90% higher rate of incidence (d𝒩/dz = 189 for log N(H I) ≥ 13.2) and a slightly shallower column density distribution function slope (−β = −1.47) relative to the general Lyα population at z = 0, reflecting the filaments’ matter over-density. The strongest Lyα absorbers are preferentially found near galaxies or close to the axis of a filament, although there is substantial scatter in this relation. Our sample of absorbers clusters more strongly around filament axes than a randomly distributed sample would do (as confirmed by a Kolmogorov–Smirnov test), but the clustering signal is less pronounced than for the galaxies in the filaments.

scholarly journals Simulations of Large-Scale Structure in the New Millennium

2005 ◽  
Vol 216 ◽  
pp. 105-119 ◽  
Author(s):  
Yasushi Suto
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Vital Role ◽  
Scale Structure ◽  
Observational Cosmology ◽  
Initial Condition ◽  
The Galaxy ◽  
The Universe ◽  
Quasar Distribution ◽  
New Millennium

Simulations of large-scale structure in the universe have played a vital role in observational cosmology since the 1980's in particular. Their important role will definitely continue to be true in the 21st century; indeed the requirements for simulations in the precision cosmology era will become more progressively demanding as they are supposed to fill the missing link in an accurate and reliable manner between the “initial” condition at z=1000 revealed by WMAP and the galaxy/quasar distribution at z=0 − 6 surveyed by 2dF and SDSS. In this review, I will summarize what we have learned so far from the previous cosmological simulations, and discuss several remaining problems for the new millennium.

scholarly journals Formation of the large-scale structure of the Universe

2011 ◽  
Vol 54 (10) ◽  
pp. 983-1005 ◽  
Author(s):  
Vladimir N Lukash ◽  
Elena V Mikheeva ◽  
A M Malinovsky
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
The Universe

The Large‐Scale Structure of the Universe

Physics Today ◽  
1981 ◽  
Vol 34 (8) ◽  
pp. 62-63 ◽  
Author(s):  
P. J. E. Peebles ◽  
Simon D. M. White
Keyword(s):  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
The Universe

scholarly journals The Theory of the Large Scale Structure of the Universe

1978 ◽  
Vol 79 ◽  
pp. 409-421 ◽  
Author(s):  
Ya B. Zeldovich
Keyword(s):  
Early Childhood ◽  
Sigmund Freud ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
The Other ◽  
Childhood Experiences ◽  
Other Hand ◽  
The Universe ◽  
Single Statement

The God-father of psychoanalysis Professor Sigmund Freud taught us that the behaviour of adults depends on their early childhood experiences. in the same spirit, the problem of cosmological analysis is to derive the observed present day situation and structure of the Universe from certain plausible assumptions about its early behaviour. Perhaps the most important single statement about the large scale structure is that there is no structure at all on the largest scale − 1000 Mpc and more. On this scale the Universe is rather uniform, structureless and isotropically expanding - just according to the simplified pictures of Einstein-Friedmann……. Humason, Hubble…. Robertson, Walker. On the other hand there is a lot of structure on the scale of 100 or 50 Mpc and less. There are clusters and superclusters of galaxies.

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