the w ilkinson m icrowave a nisotropy p robe mission
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NASA/GSFCChuck Bennett (PI)Bob Hill Gary Hinshaw Al KogutMichele LimonNils OdegardJanet WeilandEd Wollack
PrincetonChris Barnes Norm Jarosik Eiichiro KomatsuMichael Nolta
UBCMark Halpern
ChicagoStephan Meyer
BrownGreg Tucker
UCLANed Wright
Science Team:
WMAPA partnership between NASA/GSFC and Princeton
Lyman PageHiranya PeirisDavid SpergelLicia Verde
WMAP Spacecraft
MAP990422
thermally isolatedinstrument cylinder
secondaryreflectors
focal plane assemblyfeed horns
back to backGregorian optics,
1.4 x 1.6 m primaries
upper omni antenna
line of sight
deployed solar array w/ web shielding
medium gain antennae
passive thermal radiator
warm spacecraft with:- instrument electronics- attitude control/propulsion- command/data handling- battery and power control
60K
90K
300K
Why low 1/f ?
One of 20Spin rate
A-B-A-B B-A-B-A
Differential design...
….mK thermal stability
Amplifiers from NRAO, M. Pospieszalski design
Noise in maps Gaussian over five decades. Jarosik et al.
Physical temperature of receivers
20μK
−20μK
Sun referenced azimuth
WMAP computer error rate
GOES proton flux
Physical temperature of primary
Limon et al.
Trajectory
100 days to L2, 1.5e6 km from Earth.
Lunar swingbyPhasing loops
Co-rotating potential.
Official arrival date: Oct 1, 2001
Scan pattern Need to scan in a criss-cross pattern to avoid striping and to minimize pixel-pixel correlations. (Wright and Tegmark)
1) Phase switch 2.5
KHz
2) Spin at 2.2 min/rev
3)Precess through
30% of the sky in 1
hour.
4) Full sky every 6
months.
Four fold switching:
Precession Rate: 1rph22.5° half-angle
A-sideLine of sight
B-sideLine of sight
Spin rate 0.464 rpm
MAP at L2
Earth
Sun
1.5 x 108 km
North Ecliptic Pole
South Ecliptic Pole
+90° +45°
Of special importance...
1) Remove dipole from time ordered data.
2) Bin 40 days of data synchronously with the Sun position.
3) Find: ΔTrms<0.14μK
There are no corrections for spin synchronous artifacts!
Best fit model
Prediction based on TT, no free params.
cosmic variance
Temperature
Temperature-polarization
1 deg
85% of sky
The Future:
•Systematics•Refined parameters•Lensing •Polarization
http://lambda.gsfc.nasa.govData available through:
WMAP is funded for 4 y.
Satellites & BalloonPLANCK & CMBPOL
Large ground based CMB telescopes
Boomerang...
ACT, APEX, SPT, …..
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