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A New Limit on CMB Circular Polarization from SPIDER
- Source :
- The Astrophysical Journal, Volume 844 Number 2, Pages 151-157 (2017)
- Publication Year :
- 2017
-
Abstract
- We present a new upper limit on 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 non-zero circular-to-linear polarization coupling of the HWP polarization modulators, data from SPIDER's 2015 Antarctic flight provide a constraint on Stokes $V$ at 95 and 150 GHz from $33<\ell<307$. No other limits exist over this full range of angular scales, and SPIDER improves upon 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 $\mu K ^2$ to 255 $\mu K ^2$ 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.<br />Comment: 9 pages, 4 figures, 5 tables - Updated to version accepted for publication in ApJ, modified acknowledgements
Details
- Database :
- arXiv
- Journal :
- The Astrophysical Journal, Volume 844 Number 2, Pages 151-157 (2017)
- Publication Type :
- Report
- Accession number :
- edsarx.1704.00215
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.3847/1538-4357/aa7cfd