The Cosmic Microwave Background as a Probe of the Early Universe - - PowerPoint PPT Presentation

The Cosmic Microwave Background as a Probe of the Early Universe and Novel Physics

David Spergel Philadelphia March 16, 2012

Friday, March 16, 2012

Overview

What can we measure? Past Present Future

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Measuring the Initial Conditions: Simple Version

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Complexities

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What do we want to measure?

Initial conditions produced during the first moments of the universe Scalar, (Vector), and Tensor fluctuations Power spectrum Non-Gaussian features (bispectrum to bubble collisions)

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WMAP Spacecraft

MAP990422

thermally isolated instrument cylinder secondary reflectors focal plane assembly feed horns back to back Gregorian 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

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W - 94GHz

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FOREGROUND CORRECTED MAP

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FOREGROUND CORRECTED MAP

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FOREGROUND CORRECTED MAP

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What Have We Learned?

 Simple model fits a wide

range of data (only 5 numbers)

 Age of universe:13.7 Gyr  Composition:

 Atoms: 4%  Matter: 23%  Dark Energy: 73%

 Scale Invariant

Fluctuations seed growth

• f galaxies

 First Stars formed ~200

Myr after the big bang

With WMAP7, we have narrowed the constraints on the six-dimensional parameter space by 30,000 from pre-WMAP CMB

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Today’ s Universe (Sloan Digital Sky Survey)

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THlozek et all. 2011

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All of the pieces seem to fit….

 Supernova distances  Hubble Constant  Age of Universe  Cluster Properties  Gravitational Lenses  Nuclear Abundances  Lyman alpha forest  Galaxy Velocities

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The Universe is Simple?

 Fluctuations are accurately as Gaussian, Random Phase  No evidence for spatial variations in fluctuation properties  No evidence for interaction terms  No sign of global topology

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ACT

Led by Lyman Page. Devlin (Penn) leads much of the instrumental effort. 80 scientists on 5 continents 6-meter telescope on Cerro Tocco (5190 m) in the Atacama Desert. Observing the sky at 148, 218 and 277 Ghz

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Sudeep Das for the ACT collaboration

/SPT

ACT and SPT probe smaller scales

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Improving Detectors

ACT: Observed 2008-2010; Analysis Underway ACTPOL: First light in May 2012. Survey starts in July 2012. Wide (6000 sq deg) + Deep (150 sq deg) surveys Advanced ACTPOL: Proposed next generation detectors

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ACT 148 GHz map

Radio Source Cluster Incomplete Sky Coverage Data released on lambda.gsfc.nasa.gov soon 3% of data 5 degrees

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NGC 1055

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IRAS ACT 220 GHz

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ACT Sky Coverage

2008 ACT Stripe from Marriage et al. (2011)

2009+2010

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ACT Sky Coverage

2008 ACT Stripe from Marriage et al. (2011)

2009+2010

El Gordo

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Seven or more acoustic peaks

Dunkley et al. 2011

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Early universe physics

Dunkley et al. 2011

Neutrinos: More species, longer radiation domination, changes equality redshift, suppress early acoustic oscillations and adds phase shift. SPT+WMAP: N=3.86 ± 0.42 Helium: Usually assume YP=0.24, predicted by BBN More helium decreases electron density, increasing damping. Yp= 0.30 ± 0.03 (SPT+WMAP). ρrel = 7 8 4 11 ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

4 /3

Neff ⎡ ⎣ ⎢ ⎤ ⎦ ⎥ ργ

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Clusters as Cosmological Probes

SZ signal measures integrated pressure in cluster SZ signal is redshift- independent, so an SZ- selected cluster sample should be a mass-selected sample. Potentially, number counts could be an important dark energy probe. Key step: lensing calibration Subaru Image: Takada, Miyatake, et al.

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Clusters

Measurements of N(M,z) have the potential to probe the growth rate of structure and detect non-Gaussianiaties Challenge is to convert observable to mass and be sure that it doesn’ t evolve with redshift. Eddington bias: most massive clusters are likely lower mass objects with large observational

• scatter. (Need to know the error distribution

in the 2-sigma tail)

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“El Gordo”

 Detected ¡in ¡2008 ¡ACT ¡maps ¡of ¡ Southern ¡Strip ¡(Menanteau ¡et ¡al. ¡2010, ¡ Marriage ¡et ¡al. ¡2011)

• Strongest ¡SZ ¡decrement ¡over ¡755 ¡

deg2 ¡(South ¡+ ¡Equator) ¡  OpIcal ¡follow-­‑up: ¡89 redshifts!

• Imaged ¡(griz) ¡at ¡SOAR/SOI ¡
• VLT/FORS2

 Chandra X-ray Observations

• ACIS-I, 60 ks
• Spitzer IRAC warm-phase

follow-up

• Imaged ¡at ¡3.6 ¡µm ¡and ¡4.5 ¡µm

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A Remarkable Bullet-like Cluster at z~0.87

“El Gordo”

Menanteau et al. (2011, arXiv:1109.0953)

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A Remarkable Bullet-like Cluster at z~0.87

“El Gordo”

Menanteau et al. (2011, arXiv:1109.0953)

Friday, March 16, 2012

A Remarkable Bullet-like Cluster at z~0.87

“El Gordo”

Menanteau et al. (2011, arXiv:1109.0953)

Friday, March 16, 2012

A Remarkable Bullet-like Cluster at z~0.87

“El Gordo”

Menanteau et al. (2011, arXiv:1109.0953)

Friday, March 16, 2012

A Remarkable Bullet-like Cluster at z~0.87

“El Gordo”

Menanteau et al. (2011, arXiv:1109.0953)

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“El Gordo” is Hot and Luminous!!

Core-excised Integrated spectrum

Compared with Markevitch et al. (1998)

kT = 14.5 ± 0.1 keV LX = 2.19 × 1045 erg s−1 Lbol = 1.36 × 1046 erg s−1

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“El Gordo,” Chandra Imaging

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“El Gordo,” Chandra Imaging

Wake! Cometary shape (even 2 tails!) 20-40% surface brightness suppression ≈35”x60”

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“El Gordo,” Chandra Imaging

Wake! Cometary shape (even 2 tails!) 20-40% surface brightness suppression ≈35”x60”

Low entropy, bright,

• ffset peak

Friday, March 16, 2012

“El Gordo,” Chandra Imaging

Wake! Cometary shape (even 2 tails!) 20-40% surface brightness suppression ≈35”x60”

Low entropy, bright,

• ffset peak

Steep brightness gradient

β model profile

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Rarity of ACT-CL J0102-4915 - Based

• n its exceptional mass
• Area of survey:

M200 = (2.16 ± 0.32) × 1015 h−1

70 M⊙

• Combined Mass from optical

+X-ray+SZ:

• Mortonson et al. (2011)

exclusion curves for ΛCDM and quintenssence parameter distribution.

• Cluster is unlikely in the ACT survey area alone (3σ), but is not a

highly unlikely occurrence in the ACT+SPT sky region if its mass is 1- σ or more below the nominal mass. No tension with ΛCDM, since the cluster is not unexpected in the entire sky. ACT: 755 deg2 ACT+SPT: 2800 deg2

Falsify ΛCDM All Sky

L i k e l y Unlikely

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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

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ACT Lensing Detection

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

Das et al. arXiv 1103.0419

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Direct Detection of Dark Energy from the CMB

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This is just the beginning of CMB Lensing Studies

Planck ACTPOL

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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

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Next Step: ACTPOL

Funded by NSF for 2011-2016 Camera now under construction... 25 times faster survey speed and polarization sensitivity First light in 2012 Wide survey (~4000 sq. degrees) Deep survey (5 x 25 sq degree fields)

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Why Measure High l Polarization?

More modes/more sky coverage leads to more accurate parameters. New discovery space (another e-fold of inflation) Sensitive to ionization history New Lens sheet: BB power spectrum (directly related to the convergence power spectrum) has a signal/noise of 3000 in an all-sky 0.1 uK2

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The New Frontier

Full sky polarization survey to l = 5000 would have 6 times the number of modes as Planck

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ACTPol’ s Discovery Space

1000 2000 3000 4000 20 40 60 80 100 PLANCK DEEP WIDE II

Text k = 0.2-0.4 Mpc

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es in nt nd

• n

y in .

• n

rons. ld drupole net

PIXIE

Survey the whole sky at 300 frequency channels

• ver 2.5 orders of

magnitude in frequency Sensitive to better than r~0.001 Also able to detect y and mu distortions.

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Fig D.1.2 Chemical potential µ as a function of the

• Adiabatic fluctuations in

the early universe are dissipated into heat.

• Energy input at z > 106 is

completely thermalized

• Energy input at 106 >z >

103 produces a μ distortion.

• Energy input at 106 >z >

103 produces a y

μ Distortions

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Future

How well can we do with large-scale structure? Far more modes than CMB. Calibrate with lensing. Undo non-linearities. Lyman Alpha Forest: Need to push to z > 30. Lunar science?

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