Polarization measurements for CLARREO Brian Cairns, Michael Mishchenko, Andrew Lacis.
Measurements of Degree-Scale B-mode Polarization with BICEP2 ...
Transcript of Measurements of Degree-Scale B-mode Polarization with BICEP2 ...
Measurements of Degree-Scale B-mode Polarization
with BICEP2, Keck Array, and BICEP3
Colin Bischoff, 20 March 2016, Rencontres de Moriond
E-Mode Polarization Pattern
B-Mode Polarization Pattern
CMB Polarization
Amplitude of the gravitational wave signal is parametrized by tensor-to-scalar ratio, r, which is related to the energy scale of inflation.
Other sources of B-mode polarization
Gravitational lensing by large-scale structure converts fraction of primordial E mode to B mode.
Foreground emission: • Synchrotron = low frequency
foreground • Dust = high frequency foreground • Polarized by the Galactic magnetic
field.
TT spectrum
EE spectrum
BB from lensing
BB from inflation, r = 0.001 – 0.1
Target peak of BB spectrum at scales of a
few degrees
CMB Temperature and Polarization Spectra
BICEP3 (2015-)
BICEP-3-Array (2018-)
BICEP2 and Keck Array
Lens
Nylon filterLensNb magnetic shield
Passive thermal filter
Flexible heat straps
Fridge mounting bracketRefrigeratorCamera plate
Focal plane assembly
Opt
ics
tube
Cam
era
tube
1.2 m
• Small aperture cryogenic telescope targeting degree-scale peak of inflationary B modes.
• TES bolometers coupled to phased-array antennas, 256 dual-polarization pixels at 150 GHz.
The BICEP/Keck Collaboration
Elevated Station
Dark Sector
MAPO: Keck DSL: BICEP3, SPT
Amundsen-Scott South Pole Station• High (2800m) and dry site • Exceptionally stable atmosphere • Target field (~1% of the sky) is visible 24 hours/day • Logistical support from US Antarctic Program
Ice Cube
The BICEP/Keck Collaboration
The BICEP/Keck Collaboration
Steffen Richter (BICEP2)
Robert Schwarz (Keck Array) Sam Harrison (BICEP3)
Hans Boenish (BICEP3)
Winter-overs!
BICEP2 + Keck Array 150 GHz maps
Includes data through 2014. Map depth = 50 nK deg (3.0 μK arcmin). Deepest ever maps of degree-scale polarization!
signal maps jackknife (noise) maps
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BICEP2 + Keck Array 150 GHz BB spectrum
• High significance detection of BB power
• Significant excess over lensing spectrum (red curve) at low 𝓵
• Jackknife null test is consistent with zero (blue points)
Multipole, 𝓵
𝓵 (𝓵
+1) C
𝓵 / 2
π [μ
K2 ](data through 2014)
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Detectors Designed to Scale in Frequency
95
150
220
95 GHz
150 GHz
220 GHz
95 GHz detectors installed in 2 of 5 Keck receivers for 2014 observing season
BICEP2 + Keck Array BB auto and cross-spectra
BB
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Multipole, 𝓵
𝓵 (𝓵
+1) C
𝓵 / 2
π [μ
K2 ]
30 GHz
44 GHz
70 GHz
100 GHz
143 GHz
217 GHz
353 GHz
Synchrotron foreground dominates at low frequency
Dust foreground dominates at high frequency
Planck satellite provides full-sky maps of polarization at seven frequencies (also using two low frequency polarization maps from WMAP)
30 GHz
44 GHz
70 GHz
100 GHz
143 GHz
217 GHz
353 GHz
Synchrotron foreground dominates at low frequency
Dust foreground dominates at high frequency
Planck satellite provides full-sky maps of polarization at seven frequencies (also using two low frequency polarization maps from WMAP)
BICEP/Keck field
Selected cross-spectra between BICEP2/Keck and WMAP/Planck
Strong detection of dust in BK 150 GHz x Planck 353 GHz (and to a lesser extent in BK14 150 x Planck 217 GHz)
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𝓵 (𝓵
+1) C
𝓵 / 2
π [μ
K2 ]
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Auto and cross-spectra between BICEP2 + Keck Array and all WMAP/Planck maps
• Statistics for all spectra derived from joint simulations of signal and noise.
• Calculate likelihood of a parametrized model that contains CMB and foreground signals.
• Uses priors on foreground spectral and spatial behavior (derived from Planck maps over larger sky regions).
r
Parameter Constraints
Adust Async
A syn
cA d
ust
L/L m
ax
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r < 0.09 at 95% confidence
Now beats the best constraints
from temperature
data
r Adust Async
A syn
cA d
ust
L/L m
ax
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Keck 95 GHz maps help
break CMB–dust
degeneracy
foreground spectral indices (prior dominated) dust-sync correlation
foreground spatial behavior
Parameter Constraints
BB in
𝓵~8
0 ba
ndpo
wer
, 𝓵 (𝓵
+1) C
𝓵 / 2
π [μ
K2 ]
Nominal band center [GHz]
Summary of current sensitivity
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2015 Keck Array E-mode maps including 220 GHz
Already 3x deeper than Planck 217 GHz
𝜦CDM E modes observed with high S/N at three frequencies!
Zotefoam Window
HDPE Lenses
PT-410 Pulse Tube
He4-He3 Sorption Fridge
HDPE Window
Alumina Lenses
PT-415 Pulse Tube
He4-He3 Sorption Fridge
Reflective Metal-Mesh Filters
26.4 cm Aperture 55 cm Aperture
Keck vs BICEP3 Telescope
Large Area Infrared Shaders
Thin, low loss, high thermal conductivity alumina filters and lenses with epoxy-based antireflection coating
Plug & play detector modules each with 64 pixels at 95 GHz and cold multiplexing electronics.
BICEP3 New Technology
680-mm window, fast optics (f/1.6), FOV ~28° 95 GHz beam FWHM ~0.35°
BICEP3 In Operation!
BICEP3 In Operation!
2015 Keck+BICEP3 operation configuration • Keck Array: 2 receivers @ 95 GHz, 1 @ 150 GHz, 2 @ 220 GHz • BICEP3: Partial focal plane (9 tiles) @ 95 GHz
2016 Keck+BICEP3 operating configuration • Keck Array: 1 receiver @ 150 GHz, 4 @ 220 GHz • BICEP3: Full focal plane (20 tiles) @ 95 GHz
New Data Includes: ● Keck 2015: 95 + 150 + 220 GHz ● BICEP3 2015: 95 GHz
Contours are projected constraints on r and Adust for two hypothetical best-fit points (both consistent with BK14).
Signal model includes pessimistic assumption about synchrotron foreground.
r < 0.041 at 95% confidence — or — Foregrounds only PTE = 0.6%
Projected Parameter Constraints for 2015 Analysis
BICEP3Delensing with
South Pole Telescope (10 meter primary)
BICEP3 (2015-)
BICEP-3-Array (2018-)
photo: Keith Vanderlinde