A Strategy to Minimize Dust Foregrounds in B-mode Searches
arXiv:1502.00625 · doi:10.1103/PhysRevD.91.081303
Abstract
The Planck satellite has identified several patches of sky with low polarized dust emission, obvious targets for searches for the cosmic-microwave-background (CMB) B-mode signal from inflationary gravitational waves. Still, given the Planck measurement uncertainties, the polarized dust foregrounds in these different candidate patches may differ by an order of magnitude or more. Here we show that a brief initial experiment to map these candidate patches more deeply at a single high frequency can efficiently zero in on the cleanest patch(es) and thus improve significantly the sensitivity of subsequent B-mode searches. A ground-based experiment with current detector technology operating at >~220 GHz for 3 months can efficiently identify a low-dust-amplitude patch and thus improve by up to a factor 2 or 3 on the sensitivity to cosmic B modes of the subsequent lower-frequency deep integration. A balloon experiment with current detector sensitivities covering the set of patches and operating at ~350 GHz can reach a similar result in less than two weeks. This strategy may prove crucial in accessing the smallest gravitational-wave signals possible in large-field inflation. The high-frequency data from this exploratory experiment should also provide valuable foreground templates to subsequent experiments that integrate on any of the candidate patches explored.
6 pages, 1 figure; clarifications added; version accepted as rapid communication in PRD
References in corpus (4)
- Toward an Understanding of Foreground Emission in the BICEP2 Region
- A joint analysis of Planck and BICEP2 B modes including dust polarization uncertainty
- Cosmic 21-cm Delensing of Microwave Background Polarization and the Minimum Detectable Energy Scale of Inflation
- Statistical diagnostics to identify Galactic foregrounds in B-mode maps