COMPASS: An Upper Limit on CMB Polarization at an Angular Scale of 20 arc minutes

Philip C. Farese, Giorgio Dall'Oglio, Joshua O. Gundersen, Brian G. Keating, Slade Klawikowski, Lloyd Knox, Alan Levy, Philip M. Lubin, Chris W. O'Dell, Alan Peel, Lucio Piccirillo, John Ruhl, Peter T. Timbie

Published 2003-08-19Version 1

COMPASS is an on-axis 2.6 meter telescope coupled to a correlation polarimeter operating at a wavelength of 1 cm. The entire instrument was built specifically for CMB polarization studies. We report here on observations of February 2001 - April 2001 using this system. We set an upper limit on E-mode polarized anisotropies of 33.5 uK (95% confidence limit) in the l-range 200-600.