A New Limit on CMB Circular Polarization from SPIDER

• Published in: The Astrophysical Journal
• Main Authors: Nagy, J.M., Ade, P.A.R., Amiri, M., Benton, S.J., Bergman, A.S., Bihary, R., Bock, J.J., Bond, J.R., Bryan, S.A., Chiang, H.C., Contaldi, C.R., Doré, O., Duivenvoorden, A.J., Eriksen, H.K., Farhang, M., Filippini, J.P., Fissel, L.M., Fraisse, A.A., Freese, K., Galloway, M., Gambrel, A.E., Gandilo, N.N., Ganga, K., Gudmundsson, J.E., Halpern, M., Hartley, J., Hasselfield, M., Hilton, G., Holmes, W., Hristov, V.V., Huang, Z., Irwin, K.D., Jones, W.C., Kuo, C.L., Kermish, Z.D., Li, S., Mason, P.V., Megerian, K., Moncelsi, L., Morford, T.A., Netterfield, C.B., Nolta, M., Padilla, I.L., Racine, B., Rahlin, A.S., Reintsema, C., Ruhl, J.E., Runyan, M.C., Ruud, T.M., Shariff, J.A., Soler, J.D., Song, X., Trangsrud, A., Tucker, C., Tucker, R.S., Turner, A.D., van Der List, J.F., Weber, A.C., Wehus, I.K., Wiebe, D.V., Young, E.Y.
• Other Authors: AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), SPIDER
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: cosmic background radiation; cosmic background radiation: polarization; polarization: linear; cosmic background radiation: power spectrum; SPIDER; inflation; cosmic background radiation: B-mode; spectrum: thermal; [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]; Antarc*; Antarctic
• Online Access: https://hal.science/hal-01645531; https://doi.org/10.3847/1538-4357/aa7cfd

International audience We present a new upper limit on cosmic microwave background (CMB) circular polarization from the 2015 flight of Spider, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the nonzero circular-to-linear polarization coupling of the half-wave plate polarization modulators, data from Spider's 2015 Antarctic flight provide a constraint on Stokes V at 95 and 150 GHz in the range $33\lt {\ell }\lt 307$. No other limits exist over this full range of angular scales, and Spider improves on the previous limit by several orders of magnitude, providing 95% C.L. constraints on ${\ell }({\ell }+1){C}_{{\ell }}^{{VV}}/(2\pi )$ ranging from 141 to 255 μK(2) at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain even stronger constraints on circular polarization.