scholarly journals Results from a faint QSO redshift survey

1986 ◽  
Vol 119 ◽  
pp. 37-43
Author(s):  
T. Shanks ◽  
R. Fong ◽  
B.J. Boyle ◽  
B.A. Peterson
Keyword(s):  
Correlation Function ◽  
Luminosity Function ◽  
Ultraviolet Excess ◽  
Fibre Optic ◽  
Complete Sample ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey ◽  
The Universe ◽  
Optic Coupler

We have used the FOCAP fibre optic coupler at the Anglo-Australian Telescope (AAT) to measure redshifts for a complete sample of ∼ 170 B ≤ 21m QSO's selected using the ultraviolet excess (UVX) criterion. We present preliminary estimates of the QSO luminosity function in discrete redshift ranges and show how these observations differentiate between models of QSO evolution. We have also investigated the clustering of QSOs in this complete sample by estimating the QSO 2-point correlation function and we use this to derive direct constraints on the homogeneity of the Universe at large scales.

scholarly journals The Anglo-Australian Redshift Survey

1983 ◽  
Vol 104 ◽  
pp. 175-175
Author(s):  
J. Bean ◽  
G. Efstathiou ◽  
R. S. Ellis ◽  
B. A. Peterson ◽  
T. Shanks ◽  
...  
Keyword(s):  
Correlation Function ◽  
Luminosity Function ◽  
Large Scale ◽  
Peculiar Velocities ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey ◽  
Density Inhomogeneities ◽  
The Universe

The aim of the survey is to sample a relatively large, randomly chosen volume of the Universe in order to study the large-scale distribution of galaxies using the two-point correlation function, the peculiar velocities between galaxy pairs and to provide an estimate of the galaxian luminosity function that is unaffected by density inhomogeneities and Virgo infall.

scholarly journals The Center for Astrophysics Redshift Survey: Luminosity Function and Two-Point Correlation Function

1988 ◽  
Vol 130 ◽  
pp. 519-519
Author(s):  
Valérie de Lapparent ◽  
Margaret J. Geller ◽  
John P. Huchra
Keyword(s):  
Correlation Function ◽  
Luminosity Function ◽  
Theoretical Models ◽  
Spatial Correlation Function ◽  
Correlation Lengths ◽  
Two Samples ◽  
Derived Properties ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey

We compare the luminosity function and the two-point spatial correlation function for the two slices of the CfA redshift survey extension to mB(0) ≤ 15.5 [8h ≤ RA. ≤ 17h and 26.5° ≤ DEC. ≤ 38.5°], with those for the early survey limited to mB(0) ≤ 14.5 [bII ≥ 40°, and DEC. ≥ 0°]. The derived properties of the two samples agree within the errors. The parameters of the luminosity function are M* = −19.1±0.1 and α = −1.2±0.1 for the 15.5 sample, and M* = −19.3±0.1 and α = −1.1 ± 0.1 for the 14.5 sample. We use an inhomogeneity-independent method to calculate the luminosity function. The slopes of the correlation functions for the two samples are −1.5 ± 0.35, shallower than the canonical slope of −1.8. The correlation lengths are 7.5 ± 5h−1 Mpc, larger than the correlation length of 5h−1 Mpc matched to the theoretical models. Because of the 25% uncertainty in the mean density of the 15.5 sample, the correlation function is indeterminate on scales larger than ∼ 20h−1 Mpc.

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 < 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 > 10h−1 Mpc.

scholarly journals The 2dF QSO Redshift Survey - XIV. Structure and evolution from the two-point correlation function

2005 ◽  
Vol 356 (2) ◽  
pp. 415-438 ◽  
Author(s):  
Scott M. Croom ◽  
B. J. Boyle ◽  
T. Shanks ◽  
R. J. Smith ◽  
L. Miller ◽  
...  
Keyword(s):  
Correlation Function ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey

TYPICAL SCALES IN THE CLUSTERING OF THE UNIVERSE

1995 ◽  
Vol 04 (04) ◽  
pp. 417-428
Author(s):  
LI-ZHI FANG ◽  
ZU-GAN DENG ◽  
XIAO-YANG XIA
Keyword(s):  
Correlation Function ◽  
Clusters Of Galaxies ◽  
High Confidence ◽  
Scale Free ◽  
Density Perturbations ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Periodic Components ◽  
The Universe ◽  
Characteristic Scales

The cosmic density perturbations are not completely scale-free, i.e. preferential scales should exist in the clustering of the universe. Observations do show the existence of the typical scales, namely, the distribution of various objects cannot be described by a simple fractal law. However, the standard two-point correlation function statistic is ineffective in detecting the typical scales. A better method based on identifying the periodic components in two-point correlation functions was developed. Using this method, the typical scales have been systematically searched for in samples of galaxies, clusters of galaxies, quasars and absorption lines of quasars. It showed the existence of typical scales in the range of 20–130 h−1 Mpc with high confidence. In particular, two typical scales, 60−1 Mpc and 130−1 Mpc, have been detected in all the samples being analysed. Such “universal” scales are probably the characteristic scales in the primordial fluctuations of the universe. Other theoretical implications of the detected typical scales have also been reviewed.

scholarly journals Spatial correlations of extended cosmological structures

2020 ◽  
Vol 494 (3) ◽  
pp. 3227-3234
Author(s):  
V Santucho ◽  
H E Luparello ◽  
M Lares ◽  
D G Lambas ◽  
A N Ruiz ◽  
...  
Keyword(s):  
Correlation Function ◽  
Large Scale ◽  
Relative Distribution ◽  
Spatial Correlations ◽  
Large Scale Structures ◽  
Large Structures ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Cosmic Voids ◽  
The Universe

ABSTRACT Studies of large-scale structures in the Universe, such as superstructures or cosmic voids, have been widely used to characterize the properties of the cosmic web through statistical analyses. On the other hand, the two-point correlation function of large-scale tracers such as galaxies or haloes provides a reliable statistical measure. However, this function applies to the spatial distribution of point-like objects, and therefore it is not appropriate for extended large structures that strongly depart from spherical symmetry. Here we present an analysis based on the standard correlation function formalism that can be applied to extended objects exhibiting arbitrary shapes. Following this approach, we compute the probability excess Ξ of having spheres sharing parts of cosmic structures with respect to a realization corresponding to a distribution of the same structures in random positions. For this aim, we identify superstructures defined as future virialized structures (FVSs) in semi-analytic galaxies in the MPDL2 MultiDark simulation. We have also identified cosmic voids to provide a joint study of their relative distribution with respect to the superstructures. Our analysis suggests that Ξ provides useful characterizations of the large-scale distribution, as suggested from an analysis of subsets of the simulation. Even when superstructure properties may exhibit negligible variations across the subsets, Ξ has the sensitivity to statistically distinguish sub-boxes that depart from the mean at larger scales. Thus, our methods can be applied in analysis of future surveys to provide characterizations of large-scale structure suitable to distinguish different theoretical scenarios.

scholarly journals The two-point correlation function of rich clusters of galaxies: results from an extended APM cluster redshift survey

1994 ◽  
Vol 271 (1) ◽  
pp. L47-L51 ◽  
Author(s):  
G. B. Dalton ◽  
R. A. C. Croft ◽  
G. Efstathiou ◽  
W. J. Sutherland ◽  
S. J. Maddox ◽  
...  
Keyword(s):  
Correlation Function ◽  
Clusters Of Galaxies ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey
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