The Cosmic Microwave Background as a Backlight David Spergel - - PowerPoint PPT Presentation

The Cosmic Microwave Background as a Backlight

David Spergel Princeton Marseilles July 2014

Planck vs. ACT

Consitent Parameters

P -217x217 WMAP9+ACT PLANCK+WP Spectral Index 0.9743±0.0087 0.973 ± 0.011 0.9603±0.0073 Matter Density 1.149±0.028 1.146±0.044 1.199±0.027 Baryon Density 2.231±0.033 2.260±0.040 2.205±0.028 Hubble Constant 69.5±1.4 69.7±2.0 67.3±1.2

CMB as a Backlight

We understand the CMB source plane well! Integrated Sachs-Wolfe Effect: INTEGRATED CHANGE IN GRAVITIONAL POTENTIAL Thermal Sunyaev-Zeldovich Effect: INTEGRATED PRESSURE measures integrated gas pressure

Kinematic Sunyaev-Zeldovich Effect: INTEGRATED MOMENTUM

measures integrated gas momentum trace electron distribution Gravitational Lensing of the CMB: INTEGRATED DENSITY traces matter distribution to z = 1100! cross-correlation with optical lensing!

Text

Thermal and Kinematic Sunyaev Zeldovich Effects

Kinematic SZ Effect

Hand et al. 1203.4219

Future of KSZ Effect

High l experiments can measure the KSZ signal from each galaxy with S/N of 0.1/galaxy Large scale structure surveys have millions of galaxies Because density-momentum field cross-correlations scales as P(k)/k - upcoming measurements should be able to measure the large-scale power and test whether the "missing power a" at l < 40 is a stastical fluctautions or the sign of new physics

Galaxy Clusters: Different Wavelengths

SZ Cluster Explosion

Planck, ACT, and SPT have been discovering several hundred clusters through the SZ effect This is effectively a mass-limited sample that could potentially provide a powerful tool for measuring the growth rate of structure. Challenge is accurately connecting the measured SZ signal to cluster mass.

SZ Amplitude Discrepancy

Neutrino Mass or Cluster Physics?

Using SZ+X-ray to Measure Fluctuation Amplitude

Hajian, Battaglia, DNS, et al. arXiv:1309.3282 Low redshift - well understood sample

tSZ x CMB Lensing

Introduction to the ISW effect

• Change is CMB temperature due

to time variation of gravitational potential:

• Gravitational in origin, and

therefore frequency independent

• Always produced when there is

non-negligible stress component (radiation, Dark Energy…)

• For a large cluster, expect ΔT ~ 2µK

16 Simone Ferraro (Princeton)

Poisson equation

Detection strategies

17 Simone Ferraro (Princeton)

STACKING CROSS POWER SPECTRUM

Too small to detect from CMB power spectrum

ANGULAR CORRELATION

Stacking on super-clusters/voids

18 Simone Ferraro (Princeton)

Granett et al (2008) Hern´andez-Monteagudo et al (2012) Planck XIX (2013)

Expect |ΔT| ~ 2µK, but find 9.6 ± 2.2µK, and frequency independent. A 4 σ deviation from LCDM ??

z ~ 0.5 – 0.7 Consider largest 50 superclusters 50 supervoids from SDSS LRG DR6

• Confirmed by several later

analyses on the same sample and aperture radius

• Tension drops to ~2.2 σ if

using many aperture radii

• Tension also drops to ~ 2σ if

using larger sample (936 voids), but note lower redshift / less uniform sample

• Still some mystery

19 Simone Ferraro (Princeton)

Stacking on super-clusters/voids

Planck XIX on G08 sample Planck XIX on larger sample

Cross correlations

20 Simone Ferraro (Princeton)

arXiv:1404.5102

Intervening large-scale potentials deflect CMB photons and distorts the CMB. The rms deflection is about 2.7 arcmins, but the deflections are coherent on degree scales.

Gravitational Lensing of the CMB

CMB Lensing is different...

Measure deflection rather than shear (more signal on large-scale; less on small scale) Well understood source plane at known conformal distance Behind everything Single source plane- Very poor resolution

CMB Lensing 2-pt

Lensing deflects photons and produce non-Gaussian signal: Non-trivial 4-pt function Lensing power spectrum is a measure of the amplitude of fluctuations along the line of sign

Das et al. 2011

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CMB Lensing is Exploding!

CMB Lensing cross-correlation (Smith et al. (2007) WMAP x NVSS; Hirata et al. (2008)) CMB Lensing-CMB Lensing (Das et al. (2011); van Englen et al. (2012), Planck) CMB Lensing-Optical Lensing (Hand et al. 2014) Lensing S/N has increased from ~5-10 to ~30 with SPT

25 50 75 100 ACT-I SPT-1 Planck ACTpol Large

100 70 50 20 7 6 4

E + B modes

Scalar fluctuations generate E-modes. They produce TT, TE and EE correlations Tensor fluctuations generate equal amounts of E and B

• modes. They produce TT, EE

and BB correlations Gravitational lensing rotate polarization and converts E modes into B modes.

Figure from Dodelson et al. NAS White Paper astro-ph/0902.3796

E to B lensing

Hanson et al. 2013

ACTPOL: DESIGNED TO BE A POWERFUL CMB LENSING MACHINE

Assuming no systematics other than instrumental noise, these plots show the signal and noise power spectra for the Deep and Wide configurations.

ACTPOL-DEEP: 150 sq-deg @ 3 µK-arcmin (temp) and 5 µK-arcmin (pol)

ACTPOL-WIDE: 4000 sq-deg @ 20 µK-arcmin (temp) and 28 µK-arcmin (pol)

Signal

Optimal Noise

10o

ACTPOL: DESIGNED TO BE A POWERFUL CMB LENSING MACHINE

Assuming no systematics other than instrumental noise, these plots show the signal and noise power spectra for the Deep and Wide configurations.

ACTPOL-DEEP: 150 sq-deg @ 3 µK-arcmin (temp) and 5 µK-arcmin (pol)

ACTPOL-WIDE: 4000 sq-deg @ 20 µK-arcmin (temp) and 28 µK-arcmin (pol)

Signal

Optimal Noise

Signal

Optimal Noise

HyperSuprime Camera

1.5 x 1.5 degree camera on Subaru (8.3 meter telescope) First light this summer Survey begins summer 2013 (~200-300 nights) grizY Wide survey 1500 sq deg i~25.8 Deep survey 30 sq deg i ~27 .2 (+Narrow Bands) Ultradeep survey 3 sq deg i~28 (+NB)

l cκκ HSC-HSC: Solid HSC-ACTPOL: Dashed z ~1.5 (black) z~0.8 (green) z~0.4 (cyan)

100 1000 0.0001

Future of CMB is as a Backlight

Can measure projected electron density, electron momentum, electron pressure and total mass Cross-correlations with tracers can measure electron distribution around galaxies and bias of high redshift objects Cross-correlations with optical lensing and auto- correlations can be an important tool for cosmological tool Data is improving rapidly!

Backup Slides

Dust vs. CMB

Flauger, Hill and DNS BICEP2 x BICEP2 BICEP1 x BICEP2

• Can’t distinguish between the two

based on BICEP data alone

• Level of polarization need typical for

high galactic latitude (p ~0.1)

• This is NOT a 5.9 sigma detection

BICEP2 Dust Estimates

Our Data Driven Models

• Polarization direction from starlight measurements

in region

• Polarization fraction from Boulanger maps

BICEP2 Cross-correlations

Hopefully, future experiments will 
 detect Primordial Gravitational Waves

Paper VI: 217-ds1 x 217-ds2 (shown) , 217-1x217-ds2 and 217-1x217-3 fail null test. S1-S2