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QUIET Q/U Imaging ExperimenT Osamu Tajima (KEK) QUIET collaboration 1.

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Presentation on theme: "QUIET Q/U Imaging ExperimenT Osamu Tajima (KEK) QUIET collaboration 1."— Presentation transcript:

1 QUIET Q/U Imaging ExperimenT Osamu Tajima (KEK) QUIET collaboration 1

2 Age 10  36 sec 380 Kyr 1 Myr 13.8 Gyr Inflation reconbination Dark age Begin of universe reionization Big bang CMB First star Foregronds Today Galaxies History of The Universe 2 Standard cosmology model ? ? Inflation potential × GeV V 1/4 ≈ /4 r Parameterized with “ r “ : tensor-scalar ratio (T/S) Energy scale of inflation Standard Model ? ? Grand Unified Theory GUT scale GeV Planck scale Happen to be same order !?

3 Targets of QUIET Model predictions of B-modes from the inflation E-modes l(l+1)C l /2  (uK 2 ) Lensing B-modes Primordial B-modes “Inflationary B-modes” QUIET 0.2° 〜 7° 3 Wide multipole range should be covered for ``Inflationary B-modes’’

4 Toward Inflationary B modes Good systematic error control – Inflationary BB power is less than 1/1,000,000 of TT, 1/10~1/100 or less of EE – Understanding of Foregrounds – Mitigation of experimental systematics Large fields observation – Inflationary BB is significant more than 1 o scale – Should be free from experimental 1/f noise QUIET is designed to fulfill these requirements 4

5 The QUIET Collaboration 5 countries, 14 institutes, ~50 scientists QUIET observation: Oct – Dec at Atacama, Chile (5,080m) 5

6 Observation Patches 4 CMB patches were chosen (~3% of full sky) Galaxy observation when CMB patches are not visible 6 ~20 o Visible region along earth rotation QUIET (43 GHz) WMAP (5-year) Stokes, Q Stokes, U Thus far useful for demonstration

7 CMB QUIET Telescope Receiver ( detector array inside) CMB 7 ~30cm QUIET polarization module 90 sets for 95 GHz observation

8 Constraint on Foregrounds with multi-frequency observations QUIET Other experiments 43 GHz 95 GHz QUIET’s 43GHz data is important to understand effects of Synchrotron radiations 8

9 QUIET observation at Atacama, Chile 5,080m 19 detectors at 43 GHz array sensitivity 69uKs 1/2 90 detectors at 95 GHz array sensitivity ~87uKs 1/2 ~30cm ~8 months ~1.5 years > 11,000 H 9

10 QUIET polarization detector array CMB Circuit module Septum Polarizer 3cm Detector array for 95 GHz Essence of tiny 1/f knee & good systematic error control 10 Yield of usable detectors: 95%

11 Double Mod. QUIET’s detector L R D1 D3 D2 11 11 D4 Septum polarizer LNA (HEMT) Phase switch phase flip modulation ( 4kHz & 50Hz ) 180  Coupler (±1) 90  Coupler (±i) W-band module Antenna to pick up “L”, “R” 11 CMB

12 Double Mod. D1 D3 D2 D4 QQ UU UU QQ Phase switch phase flip modulation ( 4kHz & 50Hz ) QUIET’s detector L R 11 11 gAgA gBgB Septum polarizer LNA (HEMT) 180  Coupler (±1) 90  Coupler (±i) Simultaneous detection of Stokes Q and U ! Tiny spurious polarization Imperfection of waveguide components makes tiny fake-pol. However, it doesn’t fluctuate, i.e., could be calibrated very well Precise polarization angle  = ½ tan -1 (U/Q)  ½ tan -1 (D3/D1) Stable ! No fluctuation !! 12 CMB D1  g A g B × Q D2  g A g B × U D3  g A g B × U D4  g A g B × Q Each diode response g A, g B Responsivity of LNA

13 Very small 1/f knee 13 Observing data under Chilean sky f knee << f scan Double demodulation suppressed 1/f noise !!

14 Very small 1/f knee 14 Scan freq. Noise property of experiment E-modes B-modes Measurement range QUIET is free from effects of 1/f noise !!

15 Tiny spurious polarization Median of all channels (95 GHz band): 0.2% ±0.2% (syst. error dominant) Calibration was scheduled every a few hours (~0.3% precision for each) 15  Total power response as a function of time We also performed cross calibration by using astronomical objects, e.g., Jupiter II Elevation nods QQ

16 Angle calibration: TauA x sparse-wires (cross check for relative) Absolute Relative (cross check for absolute)  angle: 0.5deg (catalog uncertainty is 0.2deg) 16 Q U Taurus T pol. = 5mK, α sky =149.9±0.2° Orientation of sinusoidal curve determines detector angle Yellow bar: precision of single calibration Measured angle of ``standard detectors’’ calibration everyday unless it was invisible No angle fluctuation !!

17 17 (cross check for relative) Absolute Relative (cross check for absolute) Angle calibration: TauA x sparse-wires Artificial calibrator, ``sparse wires’’ determined relative angles Systematic error for relative angle: 0.8 o

18 Analysis Strategy Calibration, Data Selection Filter / Map Making B-mode, E-mode spectra Validation Tests 18 Stokes Q map Stokes U map Multipole l (=180 o /  ) E-modes B-modes This is simulation

19 Blind Analysis Framework Validation Tests Analysis Strategy Calibration, Data Selection Filter / Map Making B-mode, E-mode spectra Systematic Error Check 19 “Robust” ✓ ✓ “Box Open” Un-blinding the results

20 Analysis Validation: Null Tests Divide data set into two maps, difference them. Calculate “null” power spectrum Perform 42 data divisions for 43 GHz (32 divisions for 95 GHz receiver) – Q vs. U channels – weather conditions – cryostat temperature 20 (CMB+Noise A ) - (CMB+Noise B ) (Noise A -Noise B ) Null Power Spectrum

21 Passed null tests ? YES ! No bias was detected ! – Zero-consistent mean shift ±0.02 (-0.02±0.02) for 43 GHz (95 GHz) – Distribution is consistent with MC  validation of statistical error ● data ー MC w/o any systematics Bias estimator : = C l /  l 43 GHz band receiver Mean shifts  bias detection Width  statistical error validation

22 ``Far-sidelobes’’ induced ground pickup GHz observation 95 GHz observation UGS solves Far-sidelobes Characterized by using the Sun 43 GHz receiver 95 GHz receiver One of the source of detected bias by the validation tests

23 Remove effects of ground pickup by far-sidelobes 23 x 6 different angles Take cross-correlation 10 divisions for Azimuth X 6 divisions of boresight rotations Motion of each patch

24 QUIET’s E-modes 24 Two independent analysis pipeline obtained consistent results. (Calibrations are not common partially) 43 GHz band receiver 95 GHz band receiver

25 QUIET’s B-modes GHz band receiver 95 GHz band receiver Zero-consistent power observed

26 Upper limit for B-modes Upper bounds at 95% C.L. 43 GHz band: r < GHz band: r <

27 Systematic error for B modes The smallest syst. error to date: δr<0.01 Major inflation models could be covered with large statistics 27

28 Real data shows “Foreground receiver” is important !! Good estimator for effects of Synchrotron radiation 28 WMAP 30GHz QUIET 43GHz (~1/3 of EE from  CDM) One of four patches (CMB-1) at 1 st bin ( l =25–75)  = –3.1 for extrapolation Foreground receiver did its task r = 0.02 F.G. for E-modes F.G. for B-modes QUIET(43GHz)  WMAP(30GHz) cross-correlation QUIET 95GHz

29 Summary QUIET’s target: B-modes from the inflation –Designed to minimize systematics Having Foreground receiver Very good systematic error control –Very low 1/f noise First experiment Japanese institution joined One of the best CMB polarization spectrum measurements to date. –In particular E modes “spectrum” –The lowest systematic error to date:  r < 0.01 Published papers Results with 43 GHz receiver: ApJ, 741, 111 (2011). Results with 95 GHz receiver: ApJ, 760, 145 (2013). About Instruments: ApJ, 768, 9 (2013). 29

30 30 Referee report for 95 GHz receiver results Let me congratulate the QUIET team for this impressive piece of work! The control of all systematics down to r of 0.01 is absolutely spectacular. I found the paper clearly written, and a model for future polarization based CMB papers…


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