Special Astrophysics Seminar

CMB polarimetry with BICEP/Keck Array

Grant Teply

Caltech

The BICEP/Keck Array program is a series of telescopes at South Pole designed to measure CMB polarization on degree angular scales. We will describe the instrumentation and latest results of the program. Using data collected through 2013 at 150 GHz, the BICEP2+Keck Array polarization maps achieve noise levels of 57 nK-deg (3.4 uK-arcmin) over an effective area of 400 square degrees for a survey weight of 250,000 uK^-2. A strong excess above the lensing B-mode signal predicted by LCDM is observed, but a joint analysis with Planck finds the excess to be consistent with a galactic dust foreground. After correcting for dust, BICEP2+Keck Array continues to detect lensing B-modes at 7.0 sigma. Keck Array and the newly installed BICEP3 are actively taking data of the same field at 95 and 220 GHz for further foreground control.