Galaxy Clusters and Large Scale Structure. (Also topics will touch on gravitational lensing and dark matter) Unless noted, all figuress and equations from the textbooks Combes et al. Galaxies and Cosmology or Longair’s Galaxy Formation . Galaxy Clusters. Galaxy Clusters
(Also topics will touch on gravitational lensing and dark matter)
Unless noted, all figuress and equations from the textbooks Combes et al. Galaxies and Cosmology or Longair’s Galaxy Formation.
B-M Class I have central cD galaxy, Class III do not.
Tensor virial theorem for a self-gravitating system of collisionless point masses. Cf. Binney & Tremaine 1987.
King model fit in top panel.
Projected velocities vs anglular radius.
Bottom shows three consistent velocity dipsersion profiles, vs. radius now.
Abell 1689, Optical + X-rays
Abell 2125, X-rays only
Where w(θ) represents the excess probability of finding a galaxy at an angular distance θ from another galaxy. dΩ is a solid angle element. ng is the average galaxy surface density.
3D distribution from Geller and Huchra 1989 (using the “z-machine”). Some 14000 galaxies.
Holes up to about 50/h Mpc in size.
Las Campanas Redshift Survey, 4 times greater distances than Harvard. Over 26,000 galaxies. Similar results, with same scales for clumping, etc.
Brightest galaxies in the sky. Note local supercluster.
Slices through the 3-dimensional map of the distribution of galaxies from the Sloan Digital Sky Survey (SDSS). The earth is at the center, and each point represents a galaxy, typically containing about 100 billion stars. Galaxies are colored according to the ages of their stars, with the redder, more strongly clustered points showing galaxies that are made of older stars. The outer circle is at a distance of two billion light years. The region between the wedges was not mapped by the SDSS because dust in our own Galaxy obscures the view of the distant universe in these directions. The lower slice is thinner than the upper slice, so it contains fewer galaxies. Credit: M. Blanton and the SDSS.
Distribution of 31000 brightest radio sources (6 cm).
Simulations were performed at National Center for Supercomputer Applicationsby Andrey Kravtsov (The University of Chicago) and Anatoly Klypin (New Mexico State University).