Improved Upper Limit on Degree-scale CMB B-mode Polarization Power from the 670 Square-degree POLARBEAR Survey
S. Adachi, Tylor Adkins, M. A. O. Aguilar Faúndez, Kam Arnold, C. Baccigalupi, Darcy Barron, S. C. Chapman, K. Cheung, Y. Chinone, Kevin T. Crowley, T. Elleflot, Josquin Errard, Giulio Fabbian, Chang Feng, T. Fujino, Nicholas Galitzki, N. W. Halverson, M. Hasegawa, M. Hazumi, H. Hirose, L. Howe, J. Ito, O. Jeong, Daisuke Kaneko, N. Katayama, Brian Keating, Theodore Kisner, N. Krachmalnicoff, A. Kusaka, Adrian T. Lee, Eric V. Linder, A.I. Lonappan, Lindsay Lowry, Frederick Matsuda, T. Matsumura, Y. Minami, Masaaki Murata, H. Nishino, Yume Nishinomiya, D. Poletti, C. L. Reichardt, C. Ross, Y. Segawa, P. Siritanasak, R. Stompor, Aritoki Suzuki, O. Tajima, S. Takakura, S. Takatori, D. Tanabe, G. P. Teply, Kyohei Yamada, Y. Zhou
Abstract
Abstract We report an improved measurement of the degree-scale cosmic microwave background B -mode angular-power spectrum over 670 deg 2 sky area at 150 GHz with P olarbear . In the original analysis of the data, errors in the angle measurement of the continuously rotating half-wave plate, a polarization modulator, caused significant data loss. By introducing an angle-correction algorithm, the data volume is increased by a factor of 1.8. We report a new analysis using the larger data set. We find the measured B -mode spectrum is consistent with the ΛCDM model with Galactic dust foregrounds. We estimate the contamination of the foreground by cross-correlating our data and Planck 143, 217, and 353 GHz measurements, where its spectrum is modeled as a power law in angular scale and a modified blackbody in frequency. We place an upper limit on the tensor-to-scalar ratio r < 0.33 at 95% confidence level after marginalizing over the foreground parameters.