Cosmology Large Angular Scale Surveyor - T. Marriage for the CLASS Collaboration U. Michigan - Cosmology After Planck - Sep 24, 2013
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Cosmology Large Angular Scale Surveyor
T. Marriage for the CLASS Collaboration
U. Michigan — Cosmology After Planck — Sep 24, 2013
Wednesday, September 25, 13
CLASS
Collaborators
NASA GSFC JHU NIST
D. Chuss A. Ali H-M. Cho
K. Denis J. Appel K. Irwin
A. Kogut C. Bennett (PI) G. Hilton
N. Miller J. Eimer C. Reintsema
H. Moseley T. Essinger-Hileman
K. Rostem D. Gothe CfA-SAO
E. Wollack K. Harrington L. Zeng
C. Huang PUC de Chile
UBC
J. Karakla R. Dünner
M. Amiri
D. Larson
M. Halpern Columbia
T. Marriage
G. Hinshaw D. Araujo
D. Watts
Northwestern G. Jones
Z. Xu
G. Novak M. Limon
A. Miller
Wednesday, September 25, 13
CLASS targets CMB B-modes at large angles.
1) Recombination bump packs a lot of signal.
2) Avoids lensing B-modes.
Also E-mode Reionization Constraints
100 CAPMAP
BOOMERanG CBI
l(l+1)ClBB/2 [ K2]
10
Reionization DASI
Bump QUaD
1
WMAP QUIET
0.1 BICEP
r=0.7 e ns i ng
L
0.01 r=0.2
Grav.
0.001
r=0.01
0.0001 CLASS Noise Level
(20 uK-arcmin over 50% of total sky)
10 100 1000
Multipole Moment l
Wednesday, September 25, 13
CLASS targets CMB B-modes at large angles.
1) Recombination bump packs a lot of signal.
2) Avoids lensing B-modes.
Katayama & Komatsu 2012
Also E-mode Reionization Constraints
significant S/N in
first 10 ell
100 CAPMAP
BOOMERanG CBI
l(l+1)ClBB/2 [ K2]
10
Reionization DASI
Bump QUaD
1
WMAP QUIET
0.1 BICEP
r=0.7 e ns i ng
L
0.01 r=0.2
Grav.
0.001
r=0.01
0.0001 CLASS Noise Level
(20 uK-arcmin over 50% of total sky)
10 100 1000
Multipole Moment l
Wednesday, September 25, 13
CLASS targets CMB B-modes at large angles.
1) Recombination bump packs a lot of signal.
2) Avoids lensing B-modes.
Katayama & Komatsu 2012
Also E-mode Reionization Constraints
significant S/N in
first 10 ell
100 CAPMAP
CBI
A unique range of angular scales! BOOMERanG
l(l+1)ClBB/2 [ K2]
10
Reionization
(in a field
1
largely
Bump targeting
DASI
the recombination
QUaD peak)
CLASS is the QUIET
WMAP leader in this regime.
0.1 BICEP
r=0.7 e ns i ng
L
0.01 r=0.2
Grav.
0.001
r=0.01
0.0001 CLASS Noise Level
(20 uK-arcmin over 50% of total sky)
10 100 1000
Multipole Moment l
Wednesday, September 25, 13
PIPER Bands
1.0
Transmission
100
CLASS is an
150 GHz Band
40 GHz Band
90 GHz Band
array of 4 telescopesBOOM
Atmospheric
0.6
l(l+1)ClBB/2 [ K2]
10
operating at DASI
Reionization
Bump
0.2 three frequencies
1
WMAP
0.1 that straddle the BICEP
100 r=0.7
synch foreground
0.01 r=0.2
minimum.
Temperature ( K)
E modes dust
1
Antenna
0.001
B modes Additional
r=0.01 foreground
0.01 0.0001 constraints from
PIPER (200 GHz, 270 GHz) and
10 100 1000
Planck (217,10353 GHz) 10
Frequency (GHz) Multipole M
FigureCLASS Frequency
1: (Left:) The frequency Detectors
bands in which Resolution will observe
this instrument
Surveyforeground spectral
the Galactic 40 GHz
minimum and 72
to minimize atmospheric e
1.5o
shownDesign
is from the Atacama with 1 mm precipitable water vapor. Synchro
90 GHz 15 1200 40’
are based on WMAP 5-year data . This instrument complements the hig
Parameters 150 GHz 120 24’
of other instruments, such as PIPER, SPIDER, and EBEX so the combin
Wednesday, September 25, 13
To detect large-angle modes, CLASS needs a wide survey.
The Atacama is the best site for large sky coverage.
Polarbear
23o ACT/ABS
CLASS 65%
of
the
Extragalac9c
Sky
CLASS ALMA
APEX
NANTEN
Site
in
Atacama
Desert
is
not
far
from
the
equator:
most
of
sky
is
surveyed
at
zenith
angle
45
deg.
Wednesday, September 25, 13
To detect large-angle modes, CLASS needs a wide survey.
CLASS Survey Boundary
Galactic Mask
23o
CLASS 65%
of
the
Extragalac9c
Sky
Extragalactic Survey Region in Black
Site
in
Atacama
Desert
is
not
far
from
the
equator:
most
of
sky
is
surveyed
at
zenith
angle
45
deg.
Wednesday, September 25, 13
To detect large-angle modes, CLASS needs a wide survey.
Multiple observing angles through sky and deck rotation
23o
CLASS 65%
of
the
Extragalac9c
Sky
in the JHU highbay
Site
in
Atacama
Desert
is
not
far
from
the
equator:
most
of
sky
is
surveyed
at
zenith
angle
45
deg.
Wednesday, September 25, 13
The CLASS Way
1. Systematics control
with front end
modulation.
2. Sensitivity with high
efficiency optics and
TES bolometers cooled
to 150 mK.
3. Galactic foreground
cleaning with multi-
frequency telescope
array.
Wednesday, September 25, 13Continuous Operation
The CLASS Way with 50 μW at 100 mK
1. Systematics control
with front end
modulation.
2. Sensitivity with high
efficiency optics and
TES bolometers cooled
to 150 mK.
3. Galactic foreground
cleaning with multi-
One of the four CLASS receivers
frequency telescope (PT+DR Cooler) undergoing
array. tilt test.
Wednesday, September 25, 13The CLASS Way
1. Systematics control
with front end
modulation.
2. Sensitivity with high
efficiency optics and
TES bolometers cooled
to 150 mK.
3. Galactic foreground
cleaning with multi- 40 GHz Focal Plane Assembly.
frequency telescope
array.
Wednesday, September 25, 13The CLASS Way #1:
Systematics control
with front end
modulation
Wednesday, September 25, 13CLASS uses modulation to measure large scales.
2. The Variable-delay Polarization Modulator (VPM)
Input Port Output Port
A Variable-Delay Polarization Modulator
(VPM) is the front-end optical element.
θ
Modulates signal at ~5 Hz to separate
signal from the I-to-Q leakage of g
atmosphere and other instrument-
Wire Grid
related drift.
d
2θ Mirror
Moves
Mirror
Fig.dP/dU
1. The VPM consists of a polarizing grid placed in front of and para
dP/dQ
a planar mirror. The polarization parallel to the grid wires is reflected b
dP/dQ
grid. The orthogonal linear polarization passes through the grid and is refl
off the mirror. The two components Q are
:1st recombined
harmonic at the output port
a relative phase delay that is dependent upon the grid-mirror separatio
The wire grid spacing or pitch is indicated by g.
Q
The VPM consists of a polarizing grid positioned parallel to and in front of
V: 2nd harmonic
change in grid-mirror separation corresponds to a change in introduced phase
linear orthogonal polarizations. The device is show in Figure 1. Choosing coor
that Stokes Q gives the difference between the polarization states parallel and p
Wednesday, September 25, 13
to the VPM wires, the polarization transfer function can be expressed asCLASS uses modulation to measure large scales.
CMB Simulation
A Variable-Delay Polarization Modulator Miller et al (Prep)
(VPM) is the front-end optical element.
Modulates signal at 5-10 Hz to
separate
and signal
the results from the
are discussed in (unpolarized)
section 7.
atmosphere and other instrument-
related
larization Modulator drift.
(VPM)
Recovery with Modulation
Q
Input Port Output Port
and simple map-making
θ
i f t
Dr
g
Wire Grid
Signal
d
2θ
Mirror
*Both the atmosphere and gain time streams have 1/f2power spectra. The
t
atmosphere has an amplitude of 0.05 K at 0.1 Hz and the gain fluctuation has an
amplitude of 0.5% at 0.005 Hz.
Atmosphere + Differential Gain*
tsWednesday,
of a polarizing
September 25, 13
grid placed in front of and parallel toCLASS uses modulation to measure large scales.
CMB Simulation
A Variable-Delay Polarization Modulator Miller et al (Prep)
(VPM) is the front-end optical element.
Modulates signal at 5-10 Hz to
separate
and signal
the results from the
are discussed in (unpolarized)
section 7.
atmosphere and other instrument-
related
larization Modulator drift.
(VPM)
Recovery without Modulation
Q
Input Port Output Port
and simple map-making
θ
i f t
Dr
g
Wire Grid
Signal
d
2θ
Mirror
*Both the atmosphere and gain time streams have 1/f2power spectra. The
t
atmosphere has an amplitude of 0.05 K at 0.1 Hz and the gain fluctuation has an
amplitude of 0.5% at 0.005 Hz.
Atmosphere + Differential Gain*
tsWednesday,
of a polarizing
September 25, 13
grid placed in front of and parallel toCLASS uses modulation to measure large scales.
CMB Simulation
Miller et al (Prep)
200μ pitch
Recovery without Modulation
50 cm and simple map-making
Prototype
*Both the atmosphere and gain time streams have 1/f2 power spectra. The
atmosphere has an amplitude of 0.05 K at 0.1 Hz and the gain fluctuation has an
amplitude of 0.5% at 0.005 Hz. Atmosphere + Differential Gain*
Wednesday, September 25, 13Preliminary Simulation Results
EE theory, r=0.01
Effects Included:
EE systematic
BB systematic *Atmosphere
EE theory
*VPM temperature drift +
differential emissivity
BB theory r=0.01 *Detector pair differential
gain fluctuation
*VPM-Detector
misalignment (0.5 deg)
10% BB systematic due to VPM-Detector misalignment
likely further reduced by adjusting angle so EB=0
Miller et al. (in prep)
Wednesday, September 25, 13The CLASS Way #2:
Sensitivity with high
efficiency optics and
tweaked-up detectors
cooled to 150 mK
Wednesday, September 25, 13CLASS Detectors : Design Designed and made by
Horns and Planar OMT produce
simple single-moded beams.
High-efficiency and design repeatability is
achieved through use of monocrystalline silicon dielectric.
Intrinsic OMT design achieves broad 50% fractional
bandwidth, which may be divided for multi-frequency operation.
On-chip transmission line filtering, shielding and niobium gap provide
well defined bandpass and stringent blue leak control.
40 GHz Detector
Integrated backshort + Magic Tee
transmission line
shielding
Probe Antenna
Band filter
detector
chip
Wednesday, September 25, 13CLASS Detectors : Excellent Design; Excellent Tests
TESs with tuned transitions and
Detectors coupled to
thermal conductances
thermal source show
90% efficiency and no
out of band leakage.
Wollack et al. (in prep)
Wednesday, September 25, 13CLASS Detectors : Sensitivity
(or how to detect B-modes with fewer than 10,000 detectors)
Three Designs* 20
0μ
N K-
ET 150 GHz √ s
= high efficiency
Phonons
27 150 mK
0
μK
150 GHz -√ 14
modest efficiency s 0
500 mK μK
90 GHz -√
high efficiency
150 mK
s
Photons
*examples for argument; not exact; for instance need to add amplifier noise
Significant advances in SQUID amplifier noise over previous experiences.
Wednesday, September 25, 13CLASS Detectors : Sensitivity
(or how to detect B-modes with fewer than 10,000 detectors)
Three Designs* 20
0μ
N K-
ET Bicep II has 150 GHz √ s
= nearly achieved high efficiency
Phonons
27 this 150 mK
0
μK
150 GHz -√ 14 CLASS
modest efficiency s 0
500 mK μK goal
90 GHz -√
high efficiency
150 mK
s
Photons
*examples for argument; not exact; for instance need to add amplifier noise
Significant advances in SQUID amplifier noise over previous experiences.
Wednesday, September 25, 13The CLASS Way #3:
Galactic foreground
cleaning with multi-
frequency telescope array
Wednesday, September 25, 13Template-based Likelihood for r, s, and Foregrounds
(Efstathiou et al. 2009; Katayama & Komatsu 2011)
Full likelihood is computationally feasible because
we are probing large angles=fewer data with larger
signal per-alm. Approach infeasible at smaller angles.
Built-in handling of E-B mixing etc.
Wednesday, September 25, 13Galactic
Coords
40
GHz
Template cleaned map
(Noise=11 μK-arcmin)
90
GHz
Residuals from CMB
270 input map at 5nK level
GHz
(PIPER)
15 μK-arcmin noise Watts, Larson et al (in prep)
Wednesday, September 25, 13Exploring Constraints with Sky Cuts and Foregrounds
(Pixel-based likelihood as in Katayama & Komatsu 2011)
Note
Non-Gaussian
dust
rinput = 0.02
dashed lines
=
likelihood
input values using large
angular scales
can yield a
synchrotron
detection
with tail to
high r.
tensor-to-scalar ratio Watts, Larson et al (in prep)
Preliminary!!! More work to be done.
Wednesday, September 25, 13Exploring Constraints with Sky Cuts and Foregrounds
(Pixel-based likelihood as in Katayama & Komatsu 2011)
Analytic calculation (K&K ’11) Note
Non-Gaussian
dust
rinput = 0.02
dashed lines
=
likelihood
input values using large
angular scales
can yield a
synchrotron
detection
with tail to
high r.
tensor-to-scalar ratio Watts, Larson et al (in prep)
Preliminary!!! More work to be done.
Wednesday, September 25, 13Outside View on r
(Upper
limits)
Current experiment predictions
(trend ruled not just by shear
sensitivity but systematics etc)
Wednesday, September 25, 13Stay tuned! Deploying telescopes 2014-2015.
Mounts Cryostats Atacama Site Preparation
Polarbear
ACT/ABS
CLASS
Optics Focal Planes VPMs
1.5 m
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