TITLE:
CMBPol mission concept study: prospects for polarized foreground removal.
AUTHOR(S):
J. Dunkley, A. Amblard, C. Baccigalupi, M. Betoule, D. Chuss, A. Cooray, J. Delabrouille, C. Dickinson, G. Dobler, J. Dotson, H. K. Eriksen, D.
Finkbeiner, D. Fixsen, P. Fosalba, A. Fraisse, C. Hirata, A. Kogut, J. Kristiansen, C. Lawrence, A. M. Magalhaes, M. A. Miville-Deschenes, S. Meyer, A.
Miller, S. K. Naess, L. Page, H. V. Peiris, N. Phillips, E. Pierpaoli, G. Rocha, J. E. Vaillancourt, L. Verde.
DATE:
2008 Nov 24 (arXiv, v1, posted).
AVAILABILITY:
arXiv 0811.3915 (free).
PUBLICATION INFORMATION:
N/A.
ABSTRACT:
In this report we discuss the impact of polarized foregrounds on a future CMBPol satellite mission. We review our current knowledge of Galactic
polarized emission at microwave frequencies, including synchrotron and thermal dust emission. We use existing data and our understanding of the
physical behavior of the sources of foreground emission to generate sky templates, and start to assess how well primordial gravitational wave signals
can be separated from foreground contaminants for a CMBPol mission. At the estimated foreground minimum of ~100 GHz, the polarized foregrounds are
expected to be lower than a primordial polarization signal with tensor-to-scalar ratio r=0.01, in a small patch (~1%) of the sky known to have low
Galactic emission. Over 75% of the sky we expect the foreground amplitude to exceed the primordial signal by about a factor of eight at the foreground
minimum and on scales of two degrees. Only on the largest scales does the polarized foreground amplitude exceed the primordial signal by a larger
factor of about 20. The prospects for detecting an r=0.01 signal including degree-scale measurements appear promising, with 5σr~0.003
forecast
from multiple methods. A mission that observes a range of scales offers better prospects from the foregrounds perspective than one targeting only the
lowest few multipoles. We begin to explore how optimizing the composition of frequency channels in the focal plane can maximize our ability to perform
component separation, with a range of typically 40<nu<300 GHz preferred for ten channels. Foreground cleaning methods are already in place to
tackle a CMBPol mission data set, and further investigation of the optimization and detectability of the primordial signal will be useful for mission
design.
ADS BIBLIOGRAPHIC CODE: N/A.
COMMENTS: N/A.