Professor, Department of Astronomy and Astrophysics
University of Chicago

Group Contact CV SnapShots
CMB Introduction '96   Intermediate '01   Polarization Intro '01   Cosmic Symphony '04   Polarization Primer '97   Review '02   Power Animations   Lensing   Power Prehistory   Legacy Material '96   PhD Thesis '95 Baryon Acoustic Oscillations Cosmic Shear Clusters
Transfer Function WMAP Likelihood Reionization PPF for CAMB Halo Mass Conversion Cluster Abundance
Cosmology I [legacy 321] Cosmology II [321] Current Topics [282] Galaxies and Universe [242] Radiative Processes [305] Research Preparation [307] GR Perturbation Theory [408] CMB [448] Cosmic Acceleration [449]

Our Motion

Key Concepts

If we turn up the contrast on the previous map to see fluctuations at the level of one part in 1000, the COBE sky map looks like this:

Aside from some deviations about the equator, this pattern is a pure dipole.  A dipole has its maxima and minima (red and blue here) pointed in opposite directions on the sky.  This pattern is generated simply because we ourselves are moving with respect to the CMB and its temperature appears redshifted or blueshifted by the Doppler effect.

The map above has the equator placed according to where the galactic disk of the Milky way appears on the sky.  Here we begin to see contamination from our own galaxy along the equator.