South Pole Telescope

July 22, 2013: Detection of B-mode Polarization by SPTpol.

South Pole, January 10, 2012: A photograph of the SPT with the new RF shield extending past the 10 meter primary, designed to reduce ground contamination to a level below the predicted polarization signal of the CMB on few degree angular scales. SPT construction team members pose in front of the completed shield and telescope.

Photo Credit: Chris Kendall.

SPT

July, 2013: B-mode polarization detected with SPTpol.

Scientists from the South Pole Telescope (SPT) project have detected subtle distortions referred to as 'B-modes' in the polarization of the Cosmic Microwave Background (CMB, preprint here). These distortions---detected for the first time in data from SPTpol, the polarization-sensitive receiver installed on the SPT in January, 2012---are thought to have only two sources: gravitational lensing of the more conventional 'E-mode' CMB polarization, and a background of gravitational waves from the epoch of cosmic inflation. The signals detected by SPTpol are due to gravitational lensing, and a sufficiently sensitive measurement of these signals will help us learn about neutrinos through their impact on the growth of structure in the universe. Successfully detecting this tiny B-mode signal also represents a major milestone along the way to using the CMB to learn about the earliest moments of the universe with the inflationary B modes.

The South Pole Telescope is funded through the National Science Foundation and the Department of Energy Office of Science.

Click here to access the SPT Summary of Data Management Principles for DOE.