QUIET Q/U Imaging ExperimenT

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

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 Phase II is planned to start in 2012, in a larger scale, improving the techniques learned during phase-I

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

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

Status and Forecast on the EE and BB characterization Science Goals

Site and Instrumentation

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%

Q BandW Band Frequency40 GHz90 GHz N° of HEMT Detectors17/284/6 Resolution28 arcmin (FWHM)12 arcmin (FWHM) Telescope TypeCrossed Dragone Module Sensitivity300 μK s½550 μK s½ Array Sensitivity70 μK s½60 μK s½ Observation PeriodOct 2008 – June 2009June 2009 – Mid 2010 ? Phase-I Summary

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

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

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

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

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

Module/OMTs Seven element demonstration array

Receiver

Calibration and Preliminary Data

Polarization 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 SKY-DIP Once/1.5 hours, Relative Gains, Stability JUPITER Once/7 days, ∆T Gains, Beam Gain Stability Temperature Calibration Strategy + supplemental measurements

Beam Shape using Jupiter Calibration

Tau A Gains Moon Polarization Fits Calibration

CMB Analysis

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

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

Phase-I, EE Power-spectra Forecasts Q W

Patch 2a Results (PRELIMINARY)

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

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

Phase-II

Phase-II Summary Ka BandQ BandW Band Frequency32 GHz40 GHz90 GHz N° of modules (P/T)16/255/61389/108 Beamsize (FWHM)28 arcmin20 arcmin8.5 arcmin Module Sensitivity165 μK s½178 μK s½364 μK s½ Beginning operations2013 ? N° of telescopes3 Telescope typeCrossed Dragone

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

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)

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

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

Systematic Errors E->B, Patch geometry