B Polarization Measurement of the CMB 19 mai 2006 B Polarization Measurement of the CMB at the Concordia Station (Dôme C) Yannick Giraud-Héraud (APC - Paris) August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop OUTLINE reminder of CMB polarization parameters challenges for CMB polarization measurements observationnal status and forthcoming observations BRAIN: an interferometer at Dôme C (Antartica) for measuring B mode polarization of the CMB August 31, 2006 2nd Sino-French workshop

Stokes Parameters  I = <|Ex|2> + <|Ey|2> WMAP3 23 GHz Ex(t) Ey(t) x’ y’  Total intensity: Linear polarization: I = <|Ex|2> + <|Ey|2> Q = <|Ex|2> - <|Ey|2> U = <|Ex’ |2> - <|Ey’ |2> August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop The E/B Decomposition Can decompose Q & U into: E-modes (even-parity): (or grad) B-modes (odd-parity): (or curl) E-modes produced by all quadrupole sources (velocity gradients and gravitational waves) B-modes produced by gravitational waves and lensing of E-modes Wayne Hu Pure E Pure B August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop Uses of CMB Polarization Tighter constraints on cosmological parameters Gravity waves from inflation nature of gravity test of inflation energy scale Planck-era physics? Lensing reconstruction constraints on Dark Energy neutrino mass measurement August 31, 2006 2nd Sino-French workshop

CMB observables as probe for inflation - r : ratio between the amplitude of tensor/scalar power spectrum WMAP3 alone: r<0.55 (95% C.L.) (WGW<2.0 10-12) (based on temperature power spectrum) - nS, nT spectral indices of scalar and tensor power spectrum WMAP3 alone: ns=0.987+0.019-.0.037 (no running contribution) power spectrum of type B polarized anisotropies access to primordial gravitational waves August 31, 2006 2nd Sino-French workshop

CMB polarization measurements? What can we get from CMB polarization measurements? C. Rosset August 31, 2006 2nd Sino-French workshop

CMB polarization measurements? What can we get from CMB polarization measurements? Weak lensing E mode  B mode énergie noire C. Rosset August 31, 2006 2nd Sino-French workshop

Polarization has been measured DASI, CBI, BOOMERanG and CAPMAP have all published polarization detections. WMAP DASI Lens IGW August 31, 2006 2nd Sino-French workshop

Planck, for a 14 months survey: Full sky survey CMB anisotropies Temperature and polarization Resolution: 5’ Sensitivity: ∆T/T = 2.10-6 Foregrounds 15 times more sensitive than WMAP Planck will be the ultimate experiment for T up to l  2000, for E up to l  1000 … … but will be able to detect B mode only if r is closed to its actual upper limit. Planck, for a 14 months survey: ~100µK RMS Mode E ~4µK RMS Mode B ~300nK RMS (Hu et al. 2002) r=0.7 August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop Planck Polarization (Planck Blue Book) E spectra B spectra August 31, 2006 2nd Sino-French workshop

Which objectives for the CMB physics after Planck high-angular resolution  Sunyaev-Zel’dovich effect increase the number of detectors to measure the polarized anisotropies polarisées with an optimization of the optical scheme to fight the systematic effects Probe of the inflation epoch and of the Large Scale Structures August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop Sensitivity of forthcoming observations E1 E3 E2 E1 : 1000 detectors ; 1 year ; 6’ ; 4 % of the sky E2 : 1000 detectors ; 1 year ; 1’ ; 0,4 % of the sky E3 : 1000 detectors ; 1 year ; 30’ ; 100 % of the sky August 31, 2006 2nd Sino-French workshop (Task Force on Cosmic Microwave Background Research - July 2005)

2nd Sino-French workshop Long term effort QUaD, BICEP (2005-2008) ~2005 BICEP QUaD CLOVER, EBEX, POLARBEAR, BRAIN (2008-2011) ~2008-2010 ClOVER EBEX PolarBear QUIET SAMPAN, CMBPOL (> 2018) Gravitational waves >2015 CMBpol (NASA & ESA) SAMPAN (CNES) (Ken Ganga 2004) (Kaplinghat et al. 2003) August 31, 2006 2nd Sino-French workshop

Concordia Station at Dôme C French-Italian Concordia Station at Dôme C August 31, 2006 2nd Sino-French workshop

Concordia Station at Dôme C 3 traverses (12-15 days) from Dumont d’Urville to Dôme C (1100 km) every Summer (3x150 tonnes) 4 hours flight from Terra Nova Bay with Twin Otter first Winter season from February 2006 to September 2006 with 13 overwinterers Excellent atmospheric transmission all over the year winter average pwv = 250 m Dome A Data South Pole Zhongshang No measurement during the Winter Season in mm wavelenghts: site testing needed August 31, 2006 2nd Sino-French workshop Dumont d’Urville

2nd Sino-French workshop Optical Depth for 3 sites : Chajnantor (ALMA) Pôle Sud Mauna Kea Transmission = e-t (e-1/e-3 = 7,4) 1 year Dôme C = 2 years South Pole = 5 years Atacama Plateau Peterson et al. 0211134 August 31, 2006 2nd Sino-French workshop

Polarization of the atmosphere Zeeman Effect on the oxygene lines Circular Polarization Estimation: 100µK CMB (Modes B: <300nK RMS) August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop Sky Coverage Projection of the foregrounds at 150 GHz (centered on the South Pole) The 2 circles are at declinations -40° et -80° (Dôme C at -74°30’) The upper region between the 2 circles is a potential zone for observation Ability to observe always the same part of the sky Scanning direction changes with time August 31, 2006 2nd Sino-French workshop

BRAIN The instrument at Concordia (January 2006) Collaboration France-Italy-UK (Rome, Milan, Cardiff, APC, CSNSM, CESR, IAS, LISIF) August 31, 2006 2nd Sino-French workshop

BRAIN: a prototype of bolometric interferometer Why an interferometer ? sensitivity similar to a photometer direct measurement of the Stokes parameters (e.g. Cl) differential measurement  reduction of atmospheric noise simplified optical set-up (no mirror)  reduction of systematic effects (atmosphere, far side lobes, …) Horns Ortho-Mode Transducers Phase shifters Beam combiners Bolometers August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop BRAIN : 2 STEPS - 2006-2008 1) Pathfinder Objectives: automatic monitoring of the cryogenic system (300 mK) during the Winter season achieve the control of the experiment from Europe which implies satellite telemetry (INMARSAT, IRIDIUM, …) measurement of the atmospheric noise during the Winter at 150 GHz (intensity and polarization) 2) Validation of the interferometry approach in the millimetric domain using bolometers at room temperature in the laboratory at Dôme C with 6 baselines August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop August 31, 2006 2nd Sino-French workshop (January 2006)

BRAIN 2: looking for primordial B modes Dôme C (Antartica) 3 telescopes at 90, 150 and 220 GHz 3 interferometers of 16x16 horns with bolometric read-out 50 < l < 150 Starting in 2009? R=0.1 R=0.01 R=0.001 (Clément Cressiot, 2006) August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop August 31, 2006 2nd Sino-French workshop

BOOMERanG and CBI Measurements Neither BOOMERanG nor CBI have detected any BB at the level of the EE polarization signals. This limits the foregrounds in their regions. Montroy, et al. August 31, 2006 2nd Sino-French workshop

Optique froide (Cardiff) Cornets Archeops: Prototype: August 31, 2006 2nd Sino-French workshop

Optique froide (Cardiff) Cornets Archeops: Prototype: August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop Déphaseur à 4K Responsabilité APC-LISIF Déphaseur diélectrique Actionneur piézoélectrique Statut: Simulations réalisées Design figée En réalisation au BE Tests en septembre 2005 August 31, 2006 2nd Sino-French workshop

2nd Sino-French workshop Sensitivity comparison between total power array of bolometers and bolometric interferometer Total # of photons: A: area main dish : solid angle of single pixel Total # of photons: A’: area input horn ’: solid angle of input horn sensitivity is equal when August 31, 2006 2nd Sino-French workshop