Path to CMBPol Upcoming measurem ments of CMB polarization July 1 - - PowerPoint PPT Presentation
Path to CMBPol Upcoming measurem ments of CMB polarization July 1 st , 2009 July 1 st , 2009 A. Ku Kusaka (for QUIET co collaboration) Kavli Institute for Cosmologica cal Physics, University of Chicago 1 The QUIET Experime ent
Upcoming measurem
(for QUIET co
Kavli Institute for Cosmologica
ments of CMB polarization July 1st, 2009 July 1st, 2009
Kusaka collaboration)
cal Physics, University of Chicago
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The QUIET Experime Status
Q-band observing W-band deployment
Analysis Prospects
Analysis status of Q-b Power spectrum prosp Systematic errors
ent
band data spect
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QUIET Phase-I Exp
Frequencies 44 Angular resolutions 28 / 12 Field centers and sizes 181/-39 12/-48, 4x(15×1 Telescope type Crossed Polarization Modulations Phaseswitch Polarization Modulations Phaseswitch Deck, Sky ro Detector type HE Location Chajnantor(A Instrument NEQ/U ~70 Observation start date Oct., Planned observing time 150 Projected limit on r 0.5
xperiment Summary
4 / 90 GHz 2 (FWHM) arcmin at each freq 39, 78/-39, 8, 341/-36 15) = 900 Ra/Dec (Deg) Size (Deg2) ed Dragone (4kHz&50Hz), (4kHz&50Hz), rot., Fast scan EMT Bolometer, HEMT etc. (Atacama),Chile 0 / ~60 µK s1/2, combined Q and U t., 2008 0 / 100 Elapsed / effective days .5 (?) No foreground assumed
~3cm L-R decomposition
OMT HEMT Module
“Polarimeter On Chip” Key technology for large array (JPL)
~30cm c.f. CAPMAP polarimeter
HEMT Module
Q-U simultaneous
measurement
Demodulation 1/f noise reduction
D
1/f noise reduction Systematic effect
cancellation
Double-demodulation
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L=EX+iEY R=EX−iEY
HEMT Amp. Phaseswitch 4kHz, 50Hz
+1 ±1
4kHz, 50Hz 180° Coupler 90° Coupler |L±R|2+Q −Q −U |L±iR|2+U
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1.4m primary mirror Resolution in FWHM: 13 arcmin (W-band) 28 arcmin (Q-band)
Foca (Re
28 arcmin (Q-band) Inherit CBI mount
Platelet Array (W-band) ~40cm
Primary Mirror 2nd Mirror Mount
eceiver) Electronics Box Platelet Array Mount
Mirrors & Support Structure
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Chajnantor Plateau, C 17,000’ Extremely low moistur ~1 hour drive from San Year-round access Observing throughout
, Chile
ure an Pedro de Atacama t the year (day and night)
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Stanford (KIPAC) Chicago (KICP) Fermilab Manchest Oxford Caltech JPL (KIPAC) Miami Columbia Princeton
Observa
Chajnan
5 countries, 5 countries, 13 13 insti insti
ester Oslo MPI-Bonn KEK
rvational Site
antor Plateau, Chile
stitutes, ~ stitutes, ~35 scientists 35 scientists10
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Development Q-band observi 2008, October Q-band obs. start 2 W rving W-band observing Phase-II 2009, July W-band obs. start
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More than 3000 hours of C CMB observing efficiency
Science data taking start Nov., 2009
f CMB data! cy ~ 60% (before selection)
End of Q-band obs. Jun., 2009
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QUIET
Patch size: ~15×15 deg.2 Number of patches: 4 Polarbear
Map precision on 1x1 degree pixel:
Planck: 1 µK (100 GHz) QUIET Phase-I: ~1 uK (40GHz) QUIET Phase-II: 10-1 µK (90 GHz)
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Scanning g Movie
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(measured on the sky)
Typical noise spectrum
in
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Moon
Galaxy (TT, <100 hrs) QUIET
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WMAP
Galaxy (Pol., <100 hrs)
sytematic efects not considered yet not considered yet
WMAP
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The world largest HEMT MT array polarimeter
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Q-band Rx taken apart (Jun. 16th) W-band Rx landed on mount (Jun. 19th)
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Number of pixels: 90
84 polarization pixels 6 ∆T pixels
Array sensitivity: ~60 Knee frequency: ~100
Critical ~ 40 (?)
Beam FWHM = 12 ar
0 µK*s (lab. measurement) 00 mHz (lab. measurement) arcmin
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Ta
Polarization
Noise source
Sky-dip
Gain stability
+ Supplemental measurement au A
2days, 1 pix , angle, Beam
Moon
Jupiter
∆T gain, beam
Temperature
nts (e.g., polarization wire grid)
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Moon Jupiter, Venus, RCW38 ∆T Skydip Gain stability ~7%, leaka
gain
TauA
T gain ~ ± 5%
kage ~0.2%
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Q-band (already collected) W-band (expected)
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Fake signal source
Instrumental IQ/U Gain Fluctuations Noise misestimate
EB mixing source
Avo
Polarization Angle Optics cross-polarization Q/U gain mismatch TOD filtering Geometry/weighting
Overall signal size
Overall gain calibration Beam size calibration Pointing error
Sp voidable by cross-correlation pecific to pseudo-C analysis
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CMB Signal
Observed S
Detector Noise Contamina by detector 1/
d Sky After Filtering
nation 1/f noise 1/f noise is removed by high-pass filtering
CMB power extraction
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Instrumental IQ/U
See the next slide
Gain fluctuations
Even 20% fluctuation i
Noise misestimate
Can be avoided by cro Accurate estimate is n
analysis
QUIET will have both s
pipelines n is negligible for phase-I ross-correlation technique necessary for likelihood h schemes with independent
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Q-band (19 horns)
Simulation assumi ses IQ/U leakage y have 1% of leakages ias for phase-I xpected owing to deck rotation
W-band (91horns)
ming 1% leakage
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Polarization Angle, Op
Only affects by order o
Q/U gain mismatch (S TOD filtering
No acceleration No Acceleration leads to l
Geometry/weighting (
Optics cross-polarization
r of ∆θ2 n in phase-I is better than 5˚.
(See next slide)
leakage, but negligible
(See next next slide)
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~20% gain mismatch is
negligible for phase-I.
Gain fluctuation of Gain fluctuation of
QUIET-type polarimeter is common for Q and U at the first order
Relative gain between Q
and U is stable.
For phase-II, this is just a
calibration issue over the season.
Fake B-mode due to Q/U gain mismatch
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Mixing due to finite patch
A = 1/3
Pseudo-Cl estimator w/o leakage by
Mixing due to pixelization Mixing due to patch irregularity
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Current Performance
(noise, duty cycle, 1/f)
0.018 10σ
No foreground assumed
Likely Improvements ∆r 0.005 lensing 35σ
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Leaks
∆T Pol.: should be <
OMT improvement Cancelation thanks to Precise monitoring
E B: angle error <<
Dedicated calibrator Regulation improveme
Both are manageable.
Multiplicative errors
e <<0.1%
to deck rotation
<2˚
ent
le.
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Unique RF technology
Different (perhaps better) syst
Q & U measured simultaneo Modulation:
4kHz switching in the module 4kHz switching in the module Q to U to -Q every 6 hours (fr
~6% of the sky mapped 100
Sensitivity to r = 0.01
Based on current performan Foreground treatment: Allian
Identical Patches Frequencies straddle WMAP
systematics
eously at each pixel
les les s (from sky rotation)
0 times deeper than Planck ance (noise, observing eff.) ance with POLARBEAR & ABS
P “sweet spot”
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QUIET HEMT array polarimeter
technology
Mapping CMB pol. powe Mapping CMB pol. powe Phase-I Q-band receiver has alre
W-band receiver has just Phase-II Factor ~20 scale-up of p Technology, Site, Obser
er receiver: a unique choice of wer up to ~1000 wer up to ~1000 lready collected 3000 hours of ess. ust been deployed. f phase-I serving: All proven at phase-I
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