[Bicep2-list] elliptical sidelobes II

Hi, I've updated my posting from last week: http://bicep0.caltech.edu/~spuder/analysis_logbook/analysis/20130121_ellipt… ...and made a new posting: http://bicep0.caltech.edu/~spuder/analysis_logbook/analysis/20130121_ellipt… 1) I screwed up last week and instead of simulating ellipses oriented parallel to detector pol. angles, I simulated ellipses parallel/perp. to the (r,theta vector). Thus T leaked into E and B equally. 2) I was wrong in claiming that ellipses oriented parallel/perp. to the pol. angles produce T->B leakage. As John pointed out, it in fact leaks T->E. The new posting simulates 1) ellipses oriented parallel to the pol angles; and 2) ellipses oriented at 45 degrees to the pol angles. The leakage is as expected. A 10% elliptical sidelobe with 10% power and oriented at 45 deg. to the pol. angle *does* cause noticeable spurious BB. We would not see this in beam maps. I also had a quick look at the reobserved WMAP minus B2 maps, and it looks like such a sidelobe would also *not* be noticeable in this analysis. (Actually, we see a little bit higher rms in the WMAP minus B2 maps than would be expected from WMAP noise alone. I wouldn't go so far as to claim this as evidence for a compact sidelobe, but it's interesting.) However, the elliptical sidelobe does seem to cause TB correlation of a form we do not see in the real data, so I think we can rule it out on these grounds. Nonetheless, it's something to think about. (Clem, it appears that ellipticity deprojection does *not* do anything to a compact, 3 degree sidelobe with differential ellipticity.) -Chris -- ********************************************************************** Christopher Sheehy - Graduate Student - University of Chicago University of Minnesota, Room 220 Tate, 116 Church Street S.E. Minneapolis, MN, 55455 Tel: 612-625-1802 Fax: 612-624-4578 email: csheehy(a)uchicago.edu **********************************************************************