QUaD: A CMB Polarization Experiment … First Year Results, arXiv: v1 Robert B. Friedman The University of Chicago GLCW

What I Will Attempt to Cover  CMB Pol.  What is QUaD?  Analysis Techniques.  First Year Results ( arXiv: v1) & Future GLCW

CMB Polarization Science  Curves are WMAP3  EE Polarization alone cannot compete with TT for parameters (save for  )  It’s a paradigm check  BB is the hot stuff!!!  Likely below the reach of current experiments (QUaD)  Probes inflation & foregrounds through lensing QUaD will nail these GLCW

Who is QUaD?  Chicago  Clem Pryke, Tom Culverhouse, myself, John Carlstrom, Erik Leitch (JPL), Robert Schwartz (SP)  Caltech  John Kovac, Ken Ganga (Paris), Andre Lange, Jamie Bock  Stanford  Sarah Church, Ed Wu, Jamie Hendricks, Ben Rusholme, Melanie Bowden, Keith Thompson  Cardiff  Walter Gear, Mike Zemcov, Nutan Rajguru, Angiola Orland, Peter Ade, Simon Melhuish, Lucio Piccirillo  Edinburgh  Andy Taylor, Michael Brown, Patricia Castro (Lisbon)  Maynooth  Anthony Murphy, Creidhe O’Sullivan, Gary Cahill GLCW

What is QUaD?  QUaD stands for QUEST at DASI  QUEST is the bolometer array receiver  DASI interferometer first detected polariztion  High Resolution  sensitive to modes up to l ~2500  Receiver focal plane consists of 31 Polarization Sensitive Bolometer pairs  19 at 150GHz and 12 at 100GHz.  2.6m Cassegrain focus assembly mounted on the DASI platform  tri-axial orientation; AZ, EL, DK  foam cone secondary support GLCW

The Foam Cone  Typical radio telescopes use metallic secondary support legs  Can induce spurious polarization  Foam Cone made from mm-wave transparent Zotefoam.  Axially symmetric rigid cone structure adds stability ME GLCW

Map Making  Time Ordered Data (TOD) is “field differenced” first  Cancels common ground signal  3rd order polynomial removed from raw TOD  Cuts down “1/f noise” (mostly atmosphere ie. large scale variations like clouds).  PSB pair TOD summed and differenced  Sum produces Intensity or T signal  Difference used for stokes Q & U  Inverse variance weighting applied to summations  Variance map simultaneously constructed GLCW

QUaD E and B Maps  Top Row: E & B Polarization Signal  No BB signal expected!  Bottom Row: “Deck” Jackknife … should look like noise. GLCW

Spectra Estimation Procedure  Generate random CMB realizations, observe with simulated telescope  Signal only, noise only and signal plus noise sim TOD for sum/diff  Include all known parameters and uncertainties (ie. beam shapes, polarization efficiencies, etc.)  Construct maps from sim TOD and calculate sim spectra from them  Use sims to correct observed power spectra and estimate error bars  Subtract noise power measured from noise only sim spectra  Estimate filter/beam suppression measured as the ratio of signal only sim spectra vs. input spectra  variance per band in signal plus noise spectra is the ~error GLCW

Jackknife Spectra  Jackknife tests  Difference maps from independent data sets  Frequency, Deck Angle, Scan Direction, Focal Plane and Season Should be consistent w/ ZERO! GLCW

The Future of QUaD  Preliminary 1st Season Analysis Represents 67 of ~200 days already in the can.  See results arXiv: v1  3rd Season observations currently underway.  Will likely provide at least another ~70 more days  Coming Soon…  Reduced errorbars (more time)  New and improved beam models  Better control of systematics GLCW