NRAOAOC Lunch, 15 Dec 2004

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(No Transcript)
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CBI Polarization New Results!

• Brought to you by
• S. Myers, B. Mason (NRAO),
• Readhead, T. Pearson, C. Dickinson (Caltech)
• J. Sievers, C. Contaldi, J.R. Bond (CITA)
• P. Altamirano, R. Bustos, C. Achermann (Chile)
• the CBI team!

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CMB Acoustic Peaks

• Compression driven by gravity, resisted by
  radiation
• j ladder series of harmonics projection
  corrections

peaks p ls j troughs p ls (j ½)
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CMB Polarization

• E B modes even odd parity modes on k-vector
• E (even parity, gradient, aligned 0 or 90 to
  k-vector)
• from scalar density fluctuations ? predominant!
• B (odd parity, curl, at 45 to k-vector)
• from gravity wave tensor modes, or secondaries

Courtesy Wayne Hu http//background.uchicago.edu
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Polarization Power Spectrum
Planck error boxes
Hu Dodelson ARAA 2002
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The Instrument

• 13 90-cm Cassegrain antennas
• 78 baselines
• 6-meter platform
• baselines 1m 5.51m
• 10 1 GHz channels 26-36 GHz
• HEMT amplifiers (NRAO)
• cryogenic 6K, Tsys 20 K
• Single polarization (R or L)
• polarizers from U. Chicago
• Analog correlators
• 780 complex correlators
• Field-of-view 44 arcmin
• image noise 4 mJy/bm 900s
• Resolution 4.5 10 arcmin
• configuration dependent

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CBI 20002001, WMAP, ACBAR, BIMA
Readhead et al. ApJ, 609, 498 (2004) astro-ph/0402
359
SZE Secondary
CMB Primary
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Polarization Interferometry

• CBI receivers can observe either RCP or LCP
• correlation products RR, RL, LR, or LL from
  antenna pair
• Correlations to Stokes parameters (I,Q,U,V)
• co-polar RR I V
  LL I V
• CMB not circularly polarized, ignore V (RR LL
  I)
• cross-polar RL Q i U e-i2Y LR
  Q i U ei2Y
• Stokes I,Q,U to E and B
• Q i U E i B ei2c ? RL E i
  B ei2(c-Y)
• visibility covariances
• ltRR RRgt TT ltRR RLgt TE ltRL RLgt EE
  BB
• multipole l 2p B / l for baseline B
• circularly polarized interferometer directly
  measures E and B!

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DASI 3-year polarization results

• Leitch et al. 2004 (astro-ph/0409357) 16Sep04!
• EE 6.3 s
• TE 2.9 s
• consistent w/ WMAPext model
• BB consistent with zero
• no foregrounds yet!

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CBI DASI Fields

• galactic projection image WMAP synchrotron
  (Bennett et al. 2003)

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CBI Current Polarization Data

• Observing since Sep 2002 (processed to May 2004)
• compact configuration, maximum sensitivity

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Polarization Mosaics

• I, Q, U dirty mosaic images (9m differences) 70
  sq. deg

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New CBI Polarization Power Spectra

• 7-band fits (Dl 150)
• 10-band fits (Dl 100)

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New Shaped Cl fits

• Use WMAP03 best-fit Cl in signal covariance
  matrix
• bandpower is then relative to fiducial power
  spectrum
• compute for single band encompassing all ls
• Results for CBI data (sources projected from TT
  only)
• qB 1.22 0.21 (68)
• EE likelihood vs. zero equivalent significance
  8.9 s
• Conservative - project subset out in polarization
  also
• qB 1.18 0.24 (68)
• significance 7.0 s

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Cosmology from EE Polarization

• NOTE parameter constraints dominated by higher
  precision TT from CBI 2001-2002 (and to lesser
  extent 2002-2004) data!
• To discern what polarization data is adding, will
  need to be more subtle
• Standard Cosmological Model
• EE predictable from TT
• constraints dominated by more precise TT
  measurements
• Beyond the Standard Model
• derive key parameters from EE alone check
  consistency
• add new ingredients (e.g. isocurvature)

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Breaking degeneracy

• Are temperature peaks intrinsic or dynamical?
• if dynamical (standard model) then polarization
  shifted
• if intrinsic (non-standard) then polarization
  aligned with TT
• however, would not expect EE only! still

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New CBI EE Polarization Phase

• Parameterization 1 envelope plus shiftable
  sinusoid
• fit to WMAPext fiducial spectrum using
  rational functions

f 0 EE prediction f 180 aligned with TT
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New CBI EE Polarization Phase

• Peaks in EE should be offset one-half cycle vs.
  TT
• allow amplitude a and phase ? to vary

best fit a0.94 ? 2433 (Dc21) Dc2(1,
0)0.56
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New CBI EE Polarization Phase

• Scaling model spectrum shifts by scaling l
• same envelope f,g as before

?ls-1 sound crossing angular scale
fiducial model ?0 1.046 (WMAPext)
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New CBI EE Polarization Phase

• Scaling model spectrum shifts by scaling l
• allow amplitude a and scale ? to vary

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New CBI EE Polarization Phase

• Scaling model spectrum shifts by scaling l
• allow amplitude a and scale ? to vary

zoom in one-half cycle
best fit a0.93 slice along a1 ?/?0
1.020.04 (Dc21)
cf. grand unified ? 1.0440.005 ?/?0
0.9980.005 (WMAPCBI04CBI02)
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New CBI, DASI, Capmap
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New DASI EE Polarization Phase

• Use DASI EE 5-bin bandpowers (Leitch et al. 2004)
• bin-bin covariance matrix plus approximate window
  functions

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New CBI DASI EE Phase

• Combined constraints on ? model
• DASI (Leitch et al. 2004) CBI (Readhead et al.
  2004)

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Conclusions

• CMB polarization interferometry (CBI,DASI)
• straightforward analysis RR,RL ? TT,EE,BB,TE
• polarization systematics minimized
• CMB polarization results
• EE power spectrum measured
• consistent with Standard Cosmological Model
• EE acoustic spectrum
• peaks phase one-half cycle offset from TT
• sound crossing angular scale q independently
  consistent (3)
• BB null, no polarized foregrounds detected
• TE difficult to extract in wide bins
• more data, narrower bins

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CBI Projections

• Run through 2006 EE 2.7 BB 3.5 improvement

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CBI Projections

• EE phase end of 2004 vs. end of 2006

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CBI Projections

• Will BB (lensing) be foreground limited?

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The CBI Collaboration
Caltech Team Tony Readhead (Principal
Investigator), John Cartwright, Clive Dickinson,
Alison Farmer, Russ Keeney, Brian Mason, Steve
Miller, Steve Padin (Project Scientist), Tim
Pearson, Walter Schaal, Martin Shepherd, Jonathan
Sievers, Pat Udomprasert, John Yamasaki. Operation
s in Chile Pablo Altamirano, Ricardo Bustos,
Cristobal Achermann, Tomislav Vucina, Juan Pablo
Jacob, José Cortes, Wilson Araya. Collaborators
Dick Bond (CITA), Leonardo Bronfman (University
of Chile), John Carlstrom (University of
Chicago), Simon Casassus (University of Chile),
Carlo Contaldi (CITA), Nils Halverson (University
of California, Berkeley), Bill Holzapfel
(University of California, Berkeley), Marshall
Joy (NASA's Marshall Space Flight Center), John
Kovac (University of Chicago), Erik Leitch
(University of Chicago), Jorge May (University of
Chile), Steven Myers (National Radio Astronomy
Observatory), Angel Otarola (European Southern
Observatory), Ue-Li Pen (CITA), Dmitry Pogosyan
(University of Alberta), Simon Prunet (Institut
d'Astrophysique de Paris), Clem Pryke (University
of Chicago).
The CBI Project is a collaboration between the
California Institute of Technology, the Canadian
Institute for Theoretical Astrophysics, the
National Radio Astronomy Observatory, the
University of Chicago, and the Universidad de
Chile. The project has been supported by funds
from the National Science Foundation, the
California Institute of Technology, Maxine and
Ronald Linde, Cecil and Sally Drinkward, Barbara
and Stanley Rawn Jr., the Kavli Institute,and the
Canadian Institute for Advanced Research.