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5-year Results from WMAP with a Glimpse Ahead. Gary Hinshaw NASA/GSFC From Quantum to Cosmos, Airlie Center VA, July 8 2008. WMAP Mission. WMAP’S PURPOSE –
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5-year Results from WMAP with a Glimpse Ahead Gary Hinshaw NASA/GSFC From Quantum to Cosmos, Airlie Center VA, July 8 2008
WMAP Mission WMAP’S PURPOSE – To make a detailed full-sky map of the CMB radiation anisotropy (temperature and polarization) to constrain the cosmology of our universe.
WMAP Science Team W = Wilkinson
WMAP’s Differential Receivers* 10 “Differencing Assemblies” 4 @ 94 GHz W-band 2 @ 61 GHz V-band 2 @ 41 GHz Q-band 1 @ 33 GHz Ka-band 1 @ 23 GHz K-band *based on HEMT design of M. Pospieszalski
WMAP Launch • June 30, 2001 at 3:47 EDT • Delta II Model 7425-10 • Delta Launch Number 286 • Star-48 third stage motor • Cape Canaveral Air Force Station • Pad SLC-17B
WMAP at L2 Taken with ESO 2.2 m telescope, La Silla Chile, for GAIA optical tracking test. 3 images (R,G.B) taken a few minutes apart, V=19.4.
Not to scale: Earth — L2 distance is 1% of Sun — Earth Distance 22.5° half-angle 1 hour precession cone 3 Months 129 sec. (0.464rpm) Spin A-side line of site MAP at L2 B-side line of site 6 Months - full sky coverage Earth 1 Day Sun WMAP Sky Coverage MAP990159
5-year Absolute Calibration New dipole fitting technique yields absolute gain accuracy of <0.2% (difference between red and black curves).
5-year Beam Calibration Jupiter data Physical model Residual A side B side Major effort to model beam response down to -44 dB allows us to model PSF response with factor of ~2 improvement in accuracy. (Hill et al.)
Important Dates Large scale structure – dark energy: ΩΛ, σ8 Plasma epoch – matter, radiation content: Ωb, Ωc Inflation – initial conditions: A, r, ns Dark ages → first stars – polarization: τ
5-year ΛCDM Parameters Blue curves/contours – 5-year data Grey curves/contours – 3-year data Biggest improvements in: Optical depth, τ Amplitude of fluctuations @ 8 Mpc, σ8 Matter densities, Ωbh2, Ωch2
Reionization - I Was reionization a complex process? Low-l TE and EE polarization power spectra can distinguish between different ionization histories. Plots show mean TE, EE spectra for range of reionization histories. EE TE
Reionization - II Improved polarization data improves measurement of optical depth and/or reionization redshift. Also begin to probe 2nd reionization parameter. The bulk of the reionization had to occur at z>6, thus it had to be an extended process.
Cosmic Neutrino Background Evidence for the cosmic neutrino background, “would provide the most dramatic possible confirmation of the standard model of the early universe” The First Three Minutes Steven Weinberg 1977 On seeing evidence for the cosmic neutrino background
Testing Inflation - I New limits on gravitational wave amplitude, r<0.2. Information still largely comes from shape of TT spectrum.
Testing Inflation - II “Named” inflation models are currently being put to the test. Many of the models predict an observable gravitational wave background (via the CMB B-mode polarization).
Future WMAP Operations WMAP is nearing 7 years at L2 and has been approved for 2 final years of operation. What important questions will more WMAP data help address? • Reionization - was reionization an extended process? Was the universe partially reionized at z = 20 or 30? • Dark Energy - upcoming dark energy experiments will be limited by WMAP cosmological parameter uncertainties. Additional WMAP data will improve these uncertainties. • Physics of Inflation - primordial gravity waves, primordial non-Gaussianity, deviations from scale invariance. • Also: polarized synchrotron data, radio source & planet data, calibration source for ground/balloon-based experiments
Detailed Understanding of Instrument Output counts per unit of input temperature difference changes with time due to changes in spacecraft temperature and amplifier properties. Multiple years of data help to separate these effects and improve uncertainty in the gain model. Change in instrument offset vs. time. Additional years of data improve our knowledge of the sources of offset: thermal emission, gain variation, etc. 4/24/2008 WMAP 2008 Senior Review 23
Dark Energy Growth Function Combined LSS and CMB measurements probe Dark Energy. Improvements in cluster counts (Chandra, ROSAT, SDSS, DES, Pan-STARRS, etc.) and weak lensing surveys will demand better measurements of s8 and Wm to constrain w(z). The predicted number of massive clusters (alternatively, the SZ power spectrum) scales as s87 ! Acoustic scale WMAP measures the sound horizon at z=1090. This acoustic scale is the fundamental calibration for on-going and planned baryon acoustic oscillation measurements. lA = 302.08 ± 0.84 (5 yr) → ± 0.64 (9 yr) (30% improvement) WMAP5 and the Cluster Mass Function K. Rines, A. Diaferio & P. Natarajan arXiv:0803.1843
2006 2006 2006 Chandra cluster counts: Vikhlinin et al. Closing in on s8 and Wm 2008+
Inflation Have we detected deviations from scale-invariance? ~2.5 σ Is there a running spectral index? Probably not. Is there primordial non-Gaussianity? Not yet… What is the amplitude of tensor modes (gravitational waves)? r<0.2
Future CMB From Space • Planck Spacecraft is integrated, launch is imminent! See next talk. • CMBPol High sensitivity polarization to probe gravity waves from Inflation.
Inflation and Gravity Waves - I • Inflation predicts two forms of fluctuations: • Scalar modes (density perturbations) with slope ns: • generate CMB anisotropy and lead to structure formation • Tensor modes (gravity waves) with slope nt: • generate CMB anisotropy but do not contribute to structure formation • Gravity wave amplitude, r, proportional to energy scale of inflation: • Both types of fluctuations contribute to CMB temperature anisotropy:
B – tensor only E – scalar+tensor Inflation and Gravity Waves – II • Both types of fluctuations contribute to CMB polarization anisotropy: • Scalar modes produce only “E-mode” polarization patterns, by symmetry • Tensor modes produce both “E-mode” and “B-mode” polarization patterns (see below) • The observation of B-mode polarization uniquely separates scalar and tensor modes from inflation and measures the energy scale of inflation. • Only known probe of physics at E ~ 1016 GeV… 12 orders of magnitude higher than planned accelerators.
Sensitivity & Foreground Estimates Blue band - Galactic foreground estimate from WMAP3, frequency dependent Green line - Lensing (EE→BB), frequency independent Red lines - Gravity wave signal(s) Grey shaded band - 1-sigma sensitivity for 1000-channel system with 1-yr integration, 1°FWHM resolution r=0.3 r=0.01
Candidate CMBPol Concept Multiple copies of basic polarimeter module, scaled in frequency, packaged in focal plane, co-aligned along s/c symmetry axis.
Monodromy in the CMB: Gravity Waves and String Inflation Eva Silverstein and Alexander Westphal http://arxiv.org/abs/0803.3085v2 Large-field inflation (hence gravitational waves) from string theory compactified on twisted tori.