SZE in WMAP Data Jose M. Diego

& Bruce Partridge

2010, MNRAS, 402, 1179

La Thuile, March 2012

M O T I V A T I O N

Earlier works report a smaller SZE signal in WMAP than expected from X-rays (Lieu et al 2006, Afshordi et al 2007, Atrio-Barandela et al. 2008)

Other works claim that SZE and X-rays are consistent (Mroczkowski et al. 2009)

Point sources in clusters might contaminate SZE signal. But how much ?

Can WMAP data tell us something about this ?

Earlier WorksAtrio-Barandela et al. 2008. Found evidence of a steepening in the profile

Lieu et al. 2006. Significantly less SZ than expected from X rays.

z < 0.2 Lx > 3E44

Earlier Works Mroczkowski et al. 2009. X-ray and SZE compatible with a steeper profile

Universal profile

Earlier Works Zemcov et al. 2008. SCUBA data suggests higher SZ amplitudes than inferred from lower frequencies “Smoking Gun” for PS contamination (IR) ?

Granett et al. 2008. Supervoids and superclusters. ISW or PS (radio)?

Earlier WorksSignificantlyt large “alleged” ISW

Use a large catalog of X-ray selected clusters and look for the average SZE in those clusters:

X-rays data allows for a calibration of the SZE models.

The average SZE (XR) can be more easilly modeled with scaling laws.

A large sample is important to average the CMB to zero (or as close as possible).

IDEA

CLUSTER

CMB photonsDirect and scattered

X-ray photons.

SZ and X-rays in clusters

SZ = A n T

XR = B n2 T1/2

CMB

Stacking of ROSAT and WMAP Data

BCS+eBCS+REFLEXAll-Sky flux limited ROSAT sample of 750 clusters. Fluxes from these clusters used to constrain the models.

Diffuse All Sky Maps RASSPoint Source subtracted including the 3.5 arcmin center in 40% of the clusters in the catalog. RASS maps used to constrain shape*.

Effective PSF = ROSAT PSPC + RASS 12 arcminute pixelization + HEALPIX pixelization

2.5

degr

ees

WMAP SZEQ V W

2.5 degrees

Kp0 mask. If no mask is used, signal vanishes in Q, significantly reduces in V and remains essentially the same in W but some PS residual still expected.

WMAP SZE

Effective PSF = WMAP(Gauss) + HEALPIX pixelization

Modeling X-ray and SZE in clusters

Beta-model vs AD08 Ascasibar & Diego 2008

Isothermal Beta Model

AD08 Model5 Free parameters but describes not only the pressure

but also the electron density and temperature

Ascasibar & Diego 2008Best fit to CHANDRA profiles from Vikhlinin et al. 2006

Temperatures from scaling relation when not available.

Core radii unknown. Use scaling laws.

R E S U L T S

X-ray models.

Include the following corrections

Band correction

K-correction

PCS energy response (flux to cps)

Effective PSF

BSC 3.5 arcminute masking

WMAP SZE predicted signal vs observed

Given X-ray flux constraint, SZE flux goes like rc2/3

BETA

WMAP SZE predicted signal vs observed

Given X-ray flux constraint, SZE flux goes like rc2/3

AD08

PS and/or lensing contamination ?

NVSS sources (1.45 GHz) in clusters.

It is well known that bright radio sources (AGN) exist at the heart of galaxy clusters

Lin, Partridge et al. 2009. PS at 40 GHz in clusters

About 10 mJy on average in galaxy clusters. Predicts about 7 mJy at 90 GHz SCUBA extrapolations predicts about 1 mJy or less at 90 GHz

Lensing should not be an issue. Small fraction of clusters show significant contamination

However, conclusions at WMAP frequencies depend on model for background galaxies.

Cluster “Concordance” Model. Compatible with all data sets (X-rays, WMAP, PS) ?

16 mJy 26 mJy 18 mJy

Scaling Laws between X-ray and SZE

Planck “early”

Slope about 1.15Slope depends on assumed scaling laws

C O N C L U S I O N S

SZE seen clearly in WMAP & consistent with expectations

Standard isothermal Beta-model incompatible with data.

PS contamination, profile ? Still open questions but …

Planck. Wide frequency and sky coverage will allow to subtract the CMB, study individual resolved clusters, see the most massive clusters in the Universe.

ACT/SPT good frequency coverage and superior resolution will allow detailed studies of individual clusters. Specially interesting are secondary anisotropies and PS contamination. Lensing, and Rees-Sciama would benefict from stacking analysis

Mustang and beyond . Even better resolution. Internal dynamics, lensing and maybe RS, Free-Free (both at microK level) ?

This is a Lucky time!