scholarly journals On estimating redshift and luminosity distributions in photometric redshift surveys

2007 ◽  
Vol 378 (2) ◽  
pp. 709-715 ◽  
Author(s):  
R. K. Sheth
Keyword(s):  
Photometric Redshift ◽  
Redshift Surveys

scholarly journals Testing gravity using galaxy-galaxy lensing and clustering amplitudes in KiDS-1000, BOSS, and 2dFLenS

2020 ◽  
Vol 642 ◽  
pp. A158 ◽  
Author(s):  
Chris Blake ◽  
Alexandra Amon ◽  
Marika Asgari ◽  
Maciej Bilicki ◽  
Andrej Dvornik ◽  
...  
Keyword(s):  
General Relativity ◽  
Gravitational Lensing ◽  
Large Scale ◽  
Amplitude Ratio ◽  
Matter Density ◽  
Ratio Test ◽  
Theoretical Expectation ◽  
Background Light ◽  
Photometric Redshift ◽  
Redshift Surveys

The physics of gravity on cosmological scales affects both the rate of assembly of large-scale structure and the gravitational lensing of background light through this cosmic web. By comparing the amplitude of these different observational signatures, we can construct tests that can distinguish general relativity from its potential modifications. We used the latest weak gravitational lensing dataset from the Kilo-Degree Survey, KiDS-1000, in conjunction with overlapping galaxy spectroscopic redshift surveys, BOSS and 2dFLenS, to perform the most precise existing amplitude-ratio test. We measured the associated EG statistic with 15 − 20% errors in five Δz = 0.1 tomographic redshift bins in the range 0.2 <  z <  0.7 on projected scales up to 100 h−1 Mpc. The scale-independence and redshift-dependence of these measurements are consistent with the theoretical expectation of general relativity in a Universe with matter density Ωm = 0.27 ± 0.04. We demonstrate that our results are robust against different analysis choices, including schemes for correcting the effects of source photometric redshift errors, and we compare the performance of angular and projected galaxy-galaxy lensing statistics.

scholarly journals Mapping the Cosmic Web with the largest all-sky surveys

2014 ◽  
Vol 11 (S308) ◽  
pp. 143-148
Author(s):  
Maciej Bilicki ◽  
John A. Peacock ◽  
Thomas H. Jarrett ◽  
Michelle E. Cluver ◽  
Louise Steward
Keyword(s):  
Three Dimensional ◽  
Optical Data ◽  
Microwave Background ◽  
Sky Surveys ◽  
Photometric Redshift ◽  
Redshift Surveys ◽  
Cross Correlations ◽  
Galaxy Redshift ◽  
Celestial Sphere ◽  
The Universe

AbstractOur view of the low-redshift Cosmic Web has been revolutionized by galaxy redshift surveys such as 6dFGS, SDSS and 2MRS. However, the trade-off between depth and angular coverage limits a systematic three-dimensional account of the entire sky beyond the Local Volume (z< 0.05). In order to reliably map the Universe to cosmologically significant depths over the full celestial sphere, one must draw on multiwavelength datasets and state-of-the-art photometric redshift techniques. We have undertaken a dedicated program of cross-matching the largest photometric all-sky surveys – 2MASS, WISE and SuperCOSMOS – to obtain accurate redshift estimates of millions of galaxies. The first outcome of these efforts – the 2MASS Photometric Redshift catalog (2MPZ, Bilickiet al. 2014a) – has been publicly released and includes almost 1 million galaxies with a mean redshift ofz=0.08. Here we summarize how this catalog was constructed and how using the WISE mid-infrared sample together with SuperCOSMOS optical data allows us to push to redshift shells ofz∼ 0.2 –0.3 on unprecedented angular scales. Our catalogs, with ∼ 20 million sources in total, provide access to cosmological volumes crucial for studies of local galaxy flows (clustering dipole, bulk flow) and cross-correlations with the cosmic microwave background such as the integrated Sachs-Wolfe effect or lensing studies.

scholarly journals Interactive Visualization of 3D Redshift Surveys with SDvision

2010 ◽  
Vol 6 (S277) ◽  
pp. 154-157
Author(s):  
Daniel Pomarède ◽  
Marguerite Pierre
Keyword(s):  
Software Package ◽  
Three Dimensional ◽  
Interactive Visualization ◽  
Data Reconstruction ◽  
Clusters Of Galaxies ◽  
Ray Casting ◽  
Photometric Redshifts ◽  
Photometric Redshift ◽  
Density Peaks ◽  
Redshift Surveys

AbstractThe three-dimensional visualization of redshift surveys is a key player in the comprehension of the structuration of the cosmic web. The SDvision software package, intended primarily for the visualization of massive cosmological simulations, has been extended to provide an interactive visual representation of different classes of redshift surveys, with the objective to enable direct comparisons between the rare highest-density peaks traced by the clusters of galaxies found in the XMM-LSS Survey and the densely populated catalogues of galaxy photometric redshifts. We present the various possibilities offered by this tool in terms of filtering of the data, reconstruction of density fields, interactivity and visual rendering, including various techniques such as ray-casting, isosurfaces, slicing and texturing. This is illustrated using the C1 and C2 samples of the XMM-LSS Survey, and the publicly released COSMOS and CFHTLS photometric redshift Catalogs. Comparisons with published results are presented and discussed.

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