CMB from the South Pole

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CMB from the South Pole
Past, present, and future
Hanoi, Vietnam, 9 August 2006
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• South Pole is well represented at the 2006
  Rencontres du Vietnam
• This afternoon, in PS3 (cosmology/CMB)
• K. Ganga (QUAD)
• D. Dowell (BICEP)
• Ch. Reichardt (ACBAR)
• Also, in PS1 (high energy astrophysics)
• K. Hoffman (IceCube, radio neutrino detection)
• South Pole is playing increasing central role in
  CMB studies.
• International Polar Year (IPY) 2007-2008
• Last such effort IGY 1957-1958
• 80,000 scientists from 67 countries, lead to
  founding of South Pole Station, modern
  astrophysics from Antarctica.

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Outline CMB from the Pole

• South Pole Prehistory (pre-COBE!)
• Unique features of the Pole attract scientists
• Heroic age of CMB exploration 1984-1992
• Recent history (1992-2005)
• Python (1992-1997)
• Viper/ACBAR (1997-2005)
• DASI (1999-2004)
• New Challenges
• Polarization (DASIpol), QUAD, BICEP
• Structure formation / dark energy SPT

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• Amundsen-Scott South Pole Station
• elevation 2335m
• current temp -78C
• humidity 90

• Hanoi, Vietnam
• elevation 6m
• current temp 28C
• humidity 90

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Quartiles of PWV at three Sites
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Hanoi
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Why South Pole?

• Atmosphere
• Superb atmospheric transmission and stability
• Sun shielded for 6 months continuously ( easy
  to extend longer)
• Unique geographical position
• Fields remain at constant elevation 24/7/52
• Infrastructure
• Extraordinary well run station transportation,
  communications, construction support, electrical
  power, technical support, laboratory space,
  accommodations, you name it, but FedEx doesnt
  deliver
• But, cant get there 9 months of the year
• Forces project discipline

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1984 first submm astronomy at PolePomerantz
French team Emilie
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1986-1990 First CMB efforts at PoleDragovan et
al., Bell/Princeton 90 GHz Emilie 21988 Also
Lubin, Peterson, Smoot
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All cargo arrives at South Pole in LC130
Hercules 300 flights/year x 28,000 lbs, 50
for fuel resupply
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1992 White Dish (Peterson) returns tight upper
limits at lt 1 deg. scale
Hien T. Nguyen
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CMB Anisotropy Detected in 1992
the anisotropy observed by the DMR
experiment is a direct measure of the
fluctuations produced during the Inflationary
epoch, and thus provide the earliest
observational information about the origin of the
universe, going back 10-35 seconds after the big
bang. Ned Wright et al., 1992
COBE Satellite
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Python (1992-97) first permanent CMB
installation at Pole
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1994 first CMB winter operations
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50mK 4 x 90GHz bolometer array
A hard learning curve
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Martin A. Pomerantz Observatory (MAPO)
DASI/QUAD
Viper/ACBAR
About one kilometer from the geographic pole
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Viper Telescope 2.1 m off-axis Gregorian
Skirt reflects primary spill-over to sky.
Ground shield blocks emission from ELlt 25º.
Panel lowers for low-EL observations
Large AZ chop (3) small beams (4-5?)
broad ?-space coverage (75 to 3000) with
high resolution
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Business end of the ACBAR receiver
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ACBAR and CBI were used as an extension to the
WMAP power spectrum to help break parameter
degeneracies.
Bennett et al. 2003
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What does ACBAR add to parameter estimation from
WMAP? ACBAR and CBI were used as an extension
to the WMAP power spectrum to help break
parameter degeneracies.
Spergel et al., 2003
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1999-2004 DASI
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Inside DASI
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MAPO January 2001 fully equipped modern labat
South Pole station
DASI w/ deployable ground shields
Viper/ACBAR
DASI Year 1 92 days, 16 hours/day 32 fields,
released April 2001
Aug 15, 2002 DASI polarization update ? 271
days of polarization data on 2 fields
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DASI 1st Season Results
DASI papers I, II II (astro-ph/0104488 90)
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DASI 1st Season Results
April 2001
DASI papers I, II II (astro-ph/0104488 90)
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2001 DASI/Boomerang Results

• Inflation checks
• Further strong support for flat universe
• Higher harmonic acoustic peaks detected ?
  adiabatic fluctuations (not isocurvature,
  defects)
• Nearly scale invariant initial spectrum
• What stuff makes up the universe
• 4.5 Baryons consistent with Big Bang
  Nucleosynthesis ? Physics at 1 sec and
  at 400,000 years
• 30 Dark matter
• 65 Dark energy, ?? ? consistent with
  supernovae results
• Age of the universe 14 /- 0.5 Gyr

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CMB temperature easy stuff!
Hinshaw et al, 2006
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Acoustic standing waves
Photon-baryon fluid oscillates, photon
pressure gives restoring force Seeded by
primordial fluctuations density
(scalar) Linear regime Fourier modes
evolve independently Pattern is frozen at
last scattering (z 1100, t 400,000
yrs.)
e-
A density/temperature Fourier mode
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E-mode Polarization (curl free)
Polarization parallel or perpendicular to
wave vector Density (scalar) fluctuations
generate only E-Polarization
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B-mode Polarization (curl component)
Polarization oriented at 45 degrees to wave
vector Not generated by density oscillations
(only primordial source inflationary gravity
waves)
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Level of Inflationary Gravity waves (Tensors)
black hole
event horizon scale

inflation
Energy scale of Inflation! (GUT?)
WMAPSDSS
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Choose your poison.
Boyle / Steinhardt
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2002 DASI first detects polarization of the CMB
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Polarization Present

• 9/2002
• DASI E TE ast-ph/0209478
• 2/2003
• WMAP TE ast-ph/0302213
• 9/2004
• DASI E TE ast-ph/0409357
• CAPMAP E ast-ph/0409380
• CBI E ast-ph/0409569
• 7/2005
• Boom03 E TE ast-ph/0507514
• 3/2006
• WMAP E TE ast-ph/0603450

Need MORE MUSCLE!
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E (scalar)
E (scalar)
B (lensing)
B (lensing)
reionization
reionization
B (tensor)
B (tensor)
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E (scalar)
B (lensing)
reionization
B (tensor)
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Aug 2004 QUAD focal plane assembledGoal
Planck-like instantaneous sensitivity,concentrate
d on a 80 sq. deg. survey...high S/N E-map
31 feeds
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Nov 2004 Installing QUEST rx on DASI...
A tight fit!
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LHe consumption
25L/day per experiment South Pole Station
stockpiles 20,000 L for the 9 month Winter
observing season Past two winters, LHe
has lasted through to summer resupply!
January 2005
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QUAD 1yr results (simulated!)
sims well-reproduce noise in data, 300 lt l lt 1500
Michael Brown
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BICEP a B-mode machine!
Feb 2006 working at Pole!
98 Detector Focal Plane (100 GHz and 150 GHz)
KWY
Telescope 25 cm wide-field refractor, all optics
at 4 K
Polarization-Selective Bolometers (JPL)
Fast-scan mount (5 d/s)
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29 Nov 2005 BICEP lifted home
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WMAP 3yr

• 94 GHz (W-band)
• Filtered using the BICEP azimuth-scan strategy

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BICEP 9 day! (C.L. Kuo)

• Blind pointing star camera nominal radio model
  only
• Actual pointing model to be derived from galactic
  sources (WMAP?)
• Absolute calibration from WMAP

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How well could we do?

• Use actual coverage map, observing efficiency
• Assume no hit from systematics or foregrounds

WMAPSDSS
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Sensitivity projections - buyer beware

• - Assumes no hit from systematics or foregrounds
  -
• 100 good weather days (12 in the can so far)
• Conservative guess for first season

BICEP 100-day
WMAPSDSS
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Sensitivity projections - buyer beware

• - Assumes no hit from systematics or foregrounds
  -
• 300 good weather days
• Reasonable guess for 2 - 3 seasons

BICEP 300-day
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Sensitivity projections - buyer beware

• - Assumes no hit from systematics or foregrounds
  -
• BICEP-2 upgrade antenna-coupled TES focal plane
• 512 detectors at 150 GHz, 20 degree FOV

BICEP 300-day
BICEP-2
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Sensitivity projections - buyer beware

• Array of co-pointed BICEP-2 style receivers
• One concept SPuD SPider Upgrade to DASI
• 2x100, 2x150, 1x220 GHz receivers share DASI
  BICEP mounts

BICEP 300-day
BICEP-2
SPuD
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CMB polarization Foregrounds
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r0.01
From the 2005 CMB Task Force report
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within Southern Hole dust power is 100x below
median! Foreground minimum at 150 GHz, r 0.02
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10m South Pole Telescope (SPT)

• Submm wave telescope
• 20 mm rms surface
• 1 arcsecond pointing
• off-axis gregorian
• 3 levels of shielding
• 1 m primary guard ring
• inner moving shields
• outer fixed shields
• Collaboration led by
• University of Chicago
• (Carlstrom)

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Telescope will be installed in December 2006 A
test build is underway this summer in
Texas Ground shield will be installed in
December 2007
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Number counts depend Volume (z) and growth of
structure
SZ as a probe of Structure formation
Through the SZ effect we can study Galaxy
Clusters at the epoch of their formation
1 deg2 of sky _at_ 150 GHz
Springel, White, Hernquist 2000
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dN/dz for SPT 4000 sq degree Survey (could be
done in one austral winter)
Precision measurements can in principle place
precise constraints on the Dark energy equation
of state.
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What does it take to realize this potential?

• High Resolution 1 _at_ 150 GHz
• big dish gt8m
• Mapping Speed
• ( of elements)/noise2
• At 150GHz from the ground, bolometers have
  reached background limit to sensitivity
• Large format bolometer arrays

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960 Element TES Frequency Domain Multiplexed
Bolometer Array

• Initial configuration of the array will be
• 3-90 GHz wedges,
• 2-150 GHz wedges, and
• 1-217 GHz wedge.
• In the second season, we will add at least one
  274 GHz wedge

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SPT mount / reflector in Texastest build July
2006
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Construction at the Pole is proceeding on
schedule. First light in February 2007
BICEP
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QUAD T Map vs. WMAP 3yr

• WMAP unsmoothed W-band processed through QUAD
  pipeline
• Cross-calibration!

Clem Pryke
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Conclusions

• CMB polarization is worth the effort
• QUAD is beginning its 2nd season now
• 1yr results to appear soon Improved E-mode
  measurements!
• BICEP is beginning its 1st season now. Over next
  6 months, it will teach us new things about
• Large angular scales what range is accessible
  from the ground with and without modulation
• B-mode separation gaining real experience with a
  well-characterized instrument
• Inflation? (best current limit r lt 0.28)
• Future more detectors! (more frequencies!)
• SPUD, SPIDER, SPTpol, QUIET, EBEX, Clover,
  CMBpol

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Stay tuned
Photo D. Barkats
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T spectrum traces density evolution of acoustic
oscillations in early universe.

• E spectrum features
• 102 lower
• correlated with T
• but out of phase
• peaks at smaller scales

• B spectrum features
• 102 - 103 lower still!
• gravity waves l lt 100
• lensing l gt 100

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Polarization Sensitive Bolometers (Boom03, Planck)
X and Y detectors share same filters and feeds
Semiconducting thermistors Neutron-Transmutation-
Doped Ge
Metalized absorber meshes X (back) and Y
(front) R(sheet) 377 W/square
Courtesy of Jamie Bock, NASA JPL
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Origins of QUAD

• QUEST collaboration Stanford, Caltech/JPL,
  Cardiff/UK
• Caltech/JPL provides detectors 62 PSBs
• Stanford provides focal plane/receiver
  integration
• Cardiff provides mirrors, cryostat, (telescope
  mount?)
• QUEST proposal to deploy in Chile denied!
• Early 2003, DASI begins its final season
• Suggestion to put QUEST receiver on DASI mount at
  Pole
• Proposal submitted June 2003 funded!
• QUAD QUEST And DASI

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The QUAD team

• Stanford Sarah Church, Jamie Hinderks, Ben
  Rusholme, Keith Thompson, Melanie Bowden, Ed Wu
• UK Walter Gear, Simon Melhuish, Lucio
  Piccirillo, Mike Zemcov, Nutan Rajguru, Angiola
  Orland, Peter Ade, Andy Taylor, Michael Brown,
  Patricia Castro, Anthony Murphy, Creidhe
  OSullivan, Gary Cahill
• Caltech/JPL Andrew Lange, Jamie Bock, John
  Kovac, Ken Ganga (now Paris)
• Chicago Clem Pryke, Erik Leitch (now JPL),
  Robert Friedman, John Carlstrom), Robert Schwarz
  (winterover)

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Weiner filtered E / B maps

• S/N gt 1 on E-mode structure, 500 lt l lt 1000

Clem Pryke
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QUAD 1yr concerns!

• Ground pickup is significant
• Very small in polarization, but detectable
• Can remove for sure with field differencing
• May not need to take this hit with better
  filtering
• Focus shifts due to cone expansion/contraction
  and primary has small warp
• Leads to changing beam ellipticity
• Measured, modelled, and included in sims for 2005
• Fixed for 2006 with corrective secondary
• A/B beams are not identical - center points
  offset
• Measured and included in sims

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Leakage (T and E) into B is small

• Simulations include sky coverage, filtering,
  beams
• Raw B leakage
• 102 level of E

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365
Hinshaw / CMB Task Force Report
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t, ns, r from WMAP 3yr
Spergel et al, 2006

• ns 0.95 /- 0.017
• In slow-roll Inflation, if e h,
• this means r 0.1 (detectable GWs) !

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TEAM BICEP
Caltech / JPL
Andrew Lange Ki Won Yoon Cynthia Chiang John
Kovac Chao-Lin Kuo
Jamie Bock Darren Dowell Hien Nguyen Peter
Mason Erik Leitch Viktor Hristov John
Battle
Denis Barkats
U.C. Berkeley Bill Holzapfel Yuki Takahashi
U.C. San Diego Brian Keating Evan Bierman
CEA, Grenoble Lionel Duband IAS, Paris Eric
Hivon Nicolas Ponthieu
Cardiff University Peter Ade
PI Co-I
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Inflation Instructions?!
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QUAD sensitivity
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QUAD Parameter estimation

• 300 sq. deg. Survey
• 6 months, 22 hr/day 20 loss
• 3210 hr/year
• 2 years
• High resolution E-mode measurement reduces errors
  on most parameters by factor of 2

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Jan 06 A working instrument
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Polarization calibrations

• response angles
• No astronomical sources of known polarization
  angle
• Measured with dielectric sheet calibrator to lt
  /- 0.3 degrees (Yuki Takahashi)
• Spec /- 3.5 deg B from r0.1
• cross-polar response measured using wire grids,
  near and far
• gains matched using el-nods, stability checked
  with flash lamp

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How to get inflation energy from B modes
Primordial GWB power spectrum
FRW equation tells us that
Energy density
potential energy dominates under slow-roll
conditions
The final answer
(use numerical methods to get exact
coefficients...)
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Installing QUAD primary and test cone
December 2003
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QUAD cryostat/receiver
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Calibrated scans
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Excellent long term stability
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Point sources confirm pointing
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Pipelines and Simulations Constructed

• Two complete pipelines have been written
  including fake data simulators
• To sim take cross power spectra between all
  channels and accumlate over \
• n half scans
• Then regen noise with proper
  cross correlations
• Add signal sampled from a map if desired
• Replace real data with sim and map using
  usual mapper

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Jacknife Spectra Real and Sim
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Faraday Polarization Modulators
Measured Transmission

• Work of Brian Keating/UCSD
• All Solid State
• Rapid, efficient modulation /- 45 deg
• gt30 Band-Width
• Installed in 6 out of 49 pixels for 2006

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Measuring spectral match

• Measured before shipping with
• CWRU and UCSD polarizing FTSs
• (E. Bierman)
• Important for foreground removal
• Gain match from atmosphere
• (K. Yoon)

A well-matched PSB pair ( 40 with ?? matched lt
1)
A less-well-matched pair ( 3 with ?? mismatch
1-3)
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Fourier plane comparison

• High-pass filter of sky and instrument 1/f
  preserves power at l gt 30
• Modes lost to AZ-only scanning are localized to v
  axis of uv plane
• E/B mixing effects are also uv local
• No serious problems from AZ-only scanning

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Beam maps on RCW38

• Beam size, ellipticity, pointing monitored daily,
  mapped in detail monthly

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Polarized maps of the Moon

• Limb polarization gives quadrupole Q, U

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Apr 2005 QUAD CMB observing

• 24 hour observing schedule
• 5 hours fridge cycle
• 1 hour RCW38 beam calibrations
• 2 x 9 hours 18 hours mapping CMB field
• Each 9 hour map
• Covers a strip of our 80 square deg field at one
  of 2 theta orientations
• Consists of AZ scans 7.5 degree span, 0.2
  deg/sec
• 4 scans (80 sec each), followed by calibration
  and 1.2 arcmin EL step
• Redundancies
• Hourly field difference - observe lead/trail
  fields 7.5 deg in RA over exact scan pattern with
  respect to ground
• Daily theta difference - observe same fields,
  same pattern with telescope rotated 60 deg
• Each calibration
• EL nod, 1 degree
• Calibration source (polarized) swings into
  secondary apex hole

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• Gravity waves (Tensors)
• more E than B!
• Lensing
• E into B

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Gravitational lensing of T and E
T
E
T
E
B
Hu and Okamoto/0111606
Realistic models predict 2.6' rms deflection,
coherence scale few degrees
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BICEP receiver

• Wide-field refractor
• All-cold optics 2 lenses filters
• HDPE lenses (C.D. Dowell)
• Teflon AR coated (C.L. Kuo)
• 25cm -gt 0.95, 0.63 FWHMs
• 17 FOV, high throughput
• Low instr-pol, cross-pol
• Flat, telecentric focal plane
• Ready for lithographed arrays!
• Cf. EPIC, SPIDER

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BICEP focal-plane insert
Trussed structure vacuum-gap isolate 4K feeds
from 250 mK filters, PSBs (Planck/JPL style)
144 JFET pairs (SPIRE/JPL style) fridge
4He/3He/3He, 250mK, gt 60 hours
RF-sensitive components enclosed in 4K Faraday
cage
Ki Won Yoon (2006)
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Measuring beam match

• beams mapped in highbay to -30dB
• Ongoing work
• Beam parameters characterized for each feed/PSB
  pair (H.C. Chiang)
• SPECs for pairwise match of FWHM, ellipticity
  driven by simulations of measuring B (at level of
  r0.1) (N. Ponthieu)

Differential Beam sizes, 100GHz
Differential ellipticities, 100GHz
SPEC 1.1
SPEC 2.7
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14 Oct 05 To the South Pole
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17 Nov 05 safe arrival
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15 Nov - 15 Dec 05Building a new observatory
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Sidelobe characterization

• Extremely clean optical design
• Unobstructed aperture
• Black forebaffle
• Reflective groundshield
• Sidelobes mapped in-situ using Gunn oscillators
  on 30 mast
• Also, polarized thermal sources on groundshield
  edge
• Very low ground pickup!

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BICEP field selection
21 Mar
21 Jan
1.0
1000 mK
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BICEP CMB observing

• 48 hour observing schedule
• 6 hours fridge cycle
• 6 hours mapping trans-galactic field
• 4 x 9 hours 36 hours mapping CMB field
• Each 9 hour map
• covers entire field at one of 4 boresight
  orientations
• Consists of AZ scans 75 degree span, 2.8 deg/sec
• 22 scans (60 sec each), followed by calibration
  and 0.25 degree EL step

• Each calibration
• EL nod, 1 degree
• Flash lamp on swingarm

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BICEP PSB pair SUM vs DIF maps
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Noise extrapolations

• 1140 deg2
• Apodized by large FOV
• Assume 100 good-weather days
• At map center
• 0.51 mK rms in 1 deg2

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• Why go further?
• T and E Continue
• testing the paradigm
• E adds power to
• parameter estimation
• B New physics
• GWs Inflation S.G.,
• Lensing Dark energy,
• neutrino masses,
• clean the GW signal...
• Explore limits for
• future missions!
• Foregrounds, etc...

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Atmospheric transmission
SZ
Primary CMB
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Discovery of the Cosmic Microwave Background
smoking gun evidence for the Big Bang Arno
Penzias Robert Wilson in front of the 20ft Bell
Labs antenna used to discover the CMB in
1965 Enormous impact on Cosmology