Anisotropic Galaxy Clustering in the Isotropic Universe

Dr. Zheng Zheng
Department of Physics and Astronomy
University of Utah

Contemporary spectroscopic galaxy surveys (e.g., the Sloan Digital Sky Survey, or SDSS) can map out the distribution of galaxies in the universe in great detail. The clustering of galaxies measured from such surveys has become a powerful probe of cosmology and galaxy formation and evolution.  I will talk about the anisotropic patterns seen in galaxy clustering and discuss what we can learn about cosmology and galaxy formation from such anisotropies.  I will first talk about a gravitational origin of the anisotropic clustering, known as redshift-space distortion. I will highlight our recent work with SDSS/SDSS-III clustering data on studying the relation between galaxies and dark matter halos and on discovering the difference between galaxy and halo kinematics. Then I will move to a non-gravitational origin of the anisotropic clustering of high-redshift star-forming galaxies, a completely new effect predicted by our recent work from radiative transfer study of such galaxies.  I will discuss the profound implications in using such galaxies to study cosmology and physical conditions and environments of galaxies and talk about the current observational status.