QUIET Q/U Imaging ExperimenT

1. QUIET Q/U Imaging ExperimenT

2. QUIET Project Miami Physics Conference 2009 December 16 Raul Monsalve for the QUIET Collaboration University of Miami

3. What is QUIET ? • Radiotelescope that measures intensity and polarization of the CMB • Located in Chile • Main science objective is to improve characterization of E-mode polarization and detect the difficult B-mode polarization • Two phases are planned. Phase-I is ongoing, started in August 2008. Phase II is planned to start in 2012, in a larger scale, improving the techniques learned during phase-I

4. QUIET Collaboration MANCHESTER U. CHICAGO OXFORD FERMILAB OSLO STANFORD COLUMBIA MPI-BONN JPL PRINCETON CALTECH U. MIAMI KEK SITE

5. Science Goals • We can measure the polarisation of the CMB the same way as for light • The Stokes parameters quantify the polarization properties of a light ray • I = no filter at all • Q = linear polarizer at 0 and 90° • U = linear polarizer at -45 and 45 ° • V = circular polarizer • I is just the temperature • Q and U combine to form E- and B-modes • No known physical process can generate V-polarized CMB radiation

6. Science Goals Status and Forecast on the EE and BB characterization

7. Site and Instrumentation

8. Site • Chajnantor Scientific Reserve in Chile at 5080 m above sea level • Among the best places for mm and submm astronomy • Access to CBI infrastructure • Accessible at all times • 1 hour drive from San Pedro de Atacama • Good sky coverage • For outside work bottled oxygen systems are used • Oxygen concentration in control room is increased ~27%

9. Phase-I Summary

10. Mount • Inherited from CBI • Alt-Az axes • Rotation about optical axis (boresight axis) • Elevation range limited to 43 deg < el < 87 deg

11. Optics • Crossed Dragone design • 1.4 m primary and secondary mirrors • FWHM: 28 (Q) and 12 (W) arcmin

12. Horn Arrays • Conical corrugated feed horn arrays • Excellent beam symmetry • Low sidelobe response • Low cross-polarization • Broad frequency band • Typical FWHM of ~7 deg • Built by UM

13. OMTs • Splits incoming radiation into L and R • 20% bandwidth • Low loss • High isolation on the output ports to avoid temperature-to-polarization leakage

14. Detector Modules • Heart of the receiver • Polarimeter on a chip • Automated assembly and operation • Measuring of Q and U simultaneously in each pixel • Operate at ~20K

15. Module/OMTs Seven element demonstration array

16. Receiver

17. Calibration and Preliminary Data

18. Calibration Strategy Polarization Gain Stability MOON Once/7 days, Relative Gains, Angles NOISE SOURCE Once/1.5 hours, Relative Gains, Angles TAU A Once/2 days, Absolute Gains, Angles, Beams Temperature JUPITER Once/7 days, ∆T Gains, Beam SKY-DIP Once/1.5 hours, Relative Gains, Stability + supplemental measurements

19. Calibration Beam Shape using Jupiter

20. Calibration Tau A Gains Moon Polarization Fits

21. CMB Analysis

22. Observation Regions Patch Centers • Low foreground regions in coordination with ABS, Polarbear • (Multifrequency measurements for galactic foreground removal) • Distribution to allow continuous scanning 4x(15x15)=900 [deg²]

23. Telescope Operation during Q-Band Season Average 68.1% • Downtime mainly due to: • Mechanical Problems • Generator problems • Bad weather

24. Phase-I, EE Power-spectra Forecasts Q W

25. Patch 2a Results (PRELIMINARY)

26. Other Interesting Observations Galactic Center Polarization Maps with Q-Band Data (PRELIMINARY)

27. Other Interesting Observations Galactic Center Temperature Map with Q-Band Data (PRELIMINARY) QUIET WMAP

28. Phase-II

29. Phase-II Summary

30. Phase-II Power-spectra Forecasts Current Performance Likely Improvement (noise, duty cycle, 1/f)

31. Appendix • Alternate technique to identify gravitational lensing effects (Zaldarriaga(1999), Hu(2002)) • Lens reconstruction: Lensing Deflection Field calculation from cross-correlation of E- and B-modes • Stronger constraints on cosmological parameters than using B-mode power spectrum • By measuring shape and amplitude of the Deflection power spectrum QUIET Phase-II can place constraints on parameters such as: • Neutrino mass (Maltoni, 2004) • Dark energy density (Stompor, 1999) • Spatial curvature (Stompor, 1999)

32. Summary • QUIET Science: • Experiment addressing fundamental questions in physics • Taking the CMB polarization knowledge to new levels • QUIET Status: • Largest HEMT-based focal plane array ever deployed, using state of the art MMIC packaging techniques • Phase-I observing and proposing Phase-II to start in 2012/2013

34. Systematic Errors • Overall signal size • Overall gain calibration • Beamsize calibration • Pointing error • Fake signal source • Instrumental I->Q/U : caused by OMT, 1% for Q-band. Negligible. • Gain fluctuations :up to 20% negligible for phase I. • E->B mixing source • Polarization angle : calibration better than 5% for phase I. • Optics cross polarization : only affects by order of ∆ө² • Q/U gain mismatch : relative gain between Q and U stable. • Patch geometry : finite patch, patch irregularity, pixelization

35. Systematic Errors E->B, Patch geometry