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Measure of the CMB polarization anisotropies. N. Ponthieu. Overview of current results and on going projects French participation Prospects. CMB polarization if one of the hotest topics in observationnal cosmology (See. S. Prunet’s talk)
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Measure of the CMB polarization anisotropies N. Ponthieu • Overview of current results and on going projects • French participation • Prospects
CMB polarization if one of the hotest topics in observationnal cosmology (See. S. Prunet’s talk) • Many on going projects dedicated to its measurement • 1st detections in the past 3 years !… • … but still a lot to do too !
Status and prospect of experimental projects for primordial polarization anisotropies Ground Balloon Satellite • French institutes implicated both in data analysis and instrumental developpements • Mainly Bolometer experiments… • Number of detectors increase, move towards matrices 2005 2006 2007 2008 2009 2010 2015-2020 WMAP Maxipol QUAD BICEP PolarBear Brain CMBpol Satellite EBEX QUIET Spider Planck Clover
Status and prospect of experimental projects for primordial polarization anisotropies Ground Balloon Satellite • French institutes implicated both in data analysis and instrumental developpements • Mainly Bolometer experiments… • Number of detectors increase, move towards matrices 2005 2006 2007 2008 2009 2010 2015-2020 WMAP Maxipol QUAD BICEP PolarBear Brain CMBpol Satellite EBEX QUIET Spider Planck Clover APC + LAL All IAS APC + LAL All APC IAS
Status and prospect of experimental projects for primordial polarization anisotropies Ground Balloon Satellite L4 L1 L3 L2 L5 • French institutes implicated both in data analysis and instrumental developpements • Mainly Bolometer experiments… • Number of detectors increase, move towards matrices 2005 2006 2007 2008 2009 2010 2015-2020 WMAP Maxipol QUAD BICEP PolarBear Brain CMBpol Satellite EBEX QUIET Spider Planck Clover IAS APC + LAL All APC + LAL All APC IAS
Projected sensitivities EE Clover
Projected sensitivities BB Clover Brain T/S = 0.7 T/S = 0.1 T/S = 0.01 T/S = 0.001 • Forecast sensitivities are encouraging • Control of systematics remains an issue • Foregrounds.. ?
Foregrounds : e.g. Galactic Dust • Archeops results obtained @353GHz • ~ 20% of the sky • Extrapolation to 100GHz Multi-frequency component separation helps removing dust, but Archeops results show that it is much stronger than previously anticipated Ponthieu et al, 2005, AA, in press
B mode dedicated satellite around 2020 ? • Resolution is not a true issue • Sensitivity is critical: thousands of detectors which may lead to “large” focal planes at short wavelengths, new electronics, cryogenics… • Control of systematics is critical • Ultimately full sky observation • Atmosphere makes large angular scales difficult to deal with • Foregrounds, the ultimate limit ? • The 2 bumps signature of B… Ongoing studies of a dedicated satellite lead by the US (EPIC, France Co-I) and of a mini-satellite lead by France (SAMPAN)
Conclusions • CMB Polarization is one of the hotest topics in observationnal cosmology • 1st detections have confirmed the standard cosmological paradigm and set an achievable target (E modes) • France is well involved in present and future projects • Planck HFI will give a milestone measure of the E modes (BTW, HFI calibration due next January @ IAS !) • B modes remain the Grail of this quest…
On thy noble Path thou shalt measure the Weak Lensing, confront treacherous Foregrounds, vanquish evil Systematics. But herten thy Heart for thy Earth thou mighteth neede to leave…