3 years ago

CMB Polarization B-mode Delensing with SPTpol and Herschel.

J. J. McMahon, T. M. Crawford, W. L. Holzapfel, K. K. Schaffer, J. J. Bock, B. R. Saliwanchik, J. Gallicchio, B. A. Benson, N. Harrington, A. Gilbert, S. Padin, J. D. Vieira, T. Natoli, J. E. Ruhl, R. Keisler, J. D. Hrubes, D. Li, R. Citron, J. E. Austermann, A. A. Stark, G. C. Hilton, G. P. Holder, W. L. K. Wu, C. L. Chang, A. T. Lee, J. P. Nibarger, A. Conley, E. M. Leitch, M. A. Dobbs, S. Hoover, J. W. Henning, A. Manzotti, C. Pryke, K. T. Story, W. Everett, A. T. Crites, J.T. Sayre, H. C. Chiang, N. Huang, S. Dodelson, H-M. Cho, C. L. Reichardt, J. A. Beall, K. D. Irwin, L. M. Mocanu, A. N. Bender, S. S. Meyer, Z. Hou, T. de Haan, J. E. Carlstrom, M. P. Viero, L. Knox, N. Whitehorn, J. Hubmayr, K. Vanderlinde, G. Smecher, L. E. Bleem, V. Novosad, G. Wang, N. W. Halverson, E. M. George

We present a demonstration of delensing the observed cosmic microwave background (CMB) B-mode polarization anisotropy. This process of reducing the gravitational-lensing generated B-mode component will become increasingly important for improving searches for the B modes produced by primordial gravitational waves. In this work, we delens B-mode maps constructed from multi-frequency SPTpol observations of a 90 deg$^2$ patch of sky by subtracting a B-mode template constructed from two inputs: SPTpol E-mode maps and a lensing potential map estimated from the $\textit{Herschel}$ $500\,\mu m$ map of the CIB. We find that our delensing procedure reduces the measured B-mode power spectrum by 28% in the multipole range $300 < \ell < 2300$; this is shown to be consistent with expectations from theory and simulations and to be robust against systematics. The null hypothesis of no delensing is rejected at $6.9 \sigma$. Furthermore, we build and use a suite of realistic simulations to study the general properties of the delensing process and find that the delensing efficiency achieved in this work is limited primarily by the noise in the lensing potential map. We demonstrate the importance of including realistic experimental non-idealities in the delensing forecasts used to inform instrument and survey-strategy planning of upcoming lower-noise experiments, such as CMB-S4.

Publisher URL: http://arxiv.org/abs/1701.04396

DOI: arXiv:1701.04396v3

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.