Prospects for polarized foreground removal

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. MagalhãesM. 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

    Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


    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 ≲ v ≲ 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.

    Original languageEnglish
    Title of host publicationCMB Polarization Workshop
    Subtitle of host publicationTheory and Foregrounds - CMBPol Mission Concept Study
    Number of pages43
    Publication statusPublished - 30 Nov 2009
    EventCMB Polarization Workshop: Theory And Foregrounds - Batavia, IL, United States
    Duration: 23 Jun 200826 Jun 2008


    ConferenceCMB Polarization Workshop: Theory And Foregrounds
    Country/TerritoryUnited States
    CityBatavia, IL


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