0000000001308355
AUTHOR
E. Saar
The richest superclusters. II. Galaxy populations
We study the morphology of galaxy populations of the richest superclusters from the catalogue of superclusters of galaxies in the 2dF Galaxy Redshift Survey using the luminosity density distribution and Minkowski functional V3. We compare the properties of grouped and isolated galaxies in regions of different density in superclusters. We find that in high-density cores of rich superclusters there is an excess of early type, passive galaxies, among galaxies in groups and clusters, as well as among those which do not belong to groups, while in lower density outer regions there are more blue, star-forming galaxies both in groups and among those galaxies which do not belong to groups. This also…
Multiscale Methods
The lecture introduces a trous wavelet transforms, explains how to estimate the spatial density for galaxy distributions, and, finally, how to describe the morphology of cosmological density fields. An example application of these methods to the 2dFGRS gives unexpected results.
Rich clusters from SDSS DR8
The study of the properties of galaxy clusters and their environment gives us information about the formation and evolution of galaxies, groups and clusters, and larger structures - superclusters of galaxies and the whole cosmic web. We study the relations between the multimodality of galaxy clusters drawn from the SDSS DR8 and the environment where they reside. As cluster environment we consider the global luminosity density field, supercluster membership, and supercluster morphology.
Galaxy clusters from SDSS DR8
The study of the signatures of multimodality in groups and clusters of galaxies, an environment for most of the galaxies in the Universe, gives us information about the dynamical state of clusters and about merging processes, which affect the formation and evolution of galaxies, groups and clusters, and larger structures - superclusters of galaxies and the whole cosmic web. We search for the presence of substructure, a non-Gaussian, asymmetrical velocity distribution of galaxies, and large peculiar velocities of the main galaxies in clusters with at least 50 member galaxies, drawn from the SDSS DR8. Cone search capability for table J/A+A/540/A123/table3 (Data on clusters)
Baryon Acoustic Oscillations in LRGs
Baryon Acoustic Oscillations (BAO) have been previously detected using correlation functions and power spectra of the galaxy distribution. In this work, we present a new method for the detection of the real-space structures associated with this feature. These baryon acoustic structures are spherical shells with a relatively small density contrast, surrounding high density central regions. We design a specific wavelet adapted to the search for shells, and exploit the physics of the process by making use of two different mass tracers, introducing a specific statistic to detect the BAO features. We apply our method to the detection of BAO in a galaxy sample drawn from the Sloan Digital Sky Sur…