CMB Constraints on the Intracluster Medium

1. CMB Constraints on the Intracluster Medium Niayesh Afshordi Institute for Theory and Computation Harvard College Observatory External Correlations of CMB and CosmologyFermilab, Batavia, IL

2. My Collaborators Yen-Ting Lin University of Illinois Urbana-Champaign Princeton Alastair Sanderson University of Illinois Urbana-Champaign University of Birmingham Daisuke Nagai CalTech Afshordi, Lin, & Sanderson 2005 (1st yr) Afshordi, Lin, Nagai, & Sanderson 2006 (3 yrs) in preparation CMB Constraints on the Intracluster Medium

3. Thermal Sunyaev-Zel’dovich (SZ) Effectand Intra-Cluster Medium (ICM) • Probes the thermal energy distribution of electrons in the Intra-Cluster Medium • Dominates CMB at angles < 0.1o • Generates an anti-correlation between WMAP and galaxy/cluster distribution WMAP sees here CMB Constraints on the Intracluster Medium

4. Thermal Sunyaev-Zel’dovich (SZ) Effectand the CMB Readhead et al. 2004 Tension with new low WMAP 8 ?! CMB Constraints on the Intracluster Medium

5. Can SZ surveys sustain the CMB dominance? • SZ clusters can be Detected up to high redshifts • Their number counts probe Dark Energy/Cosmology • Many SZ surveys are underway: APEX, SZA, ACT, SPT, Planck, … • Can they deliver? Calibration of SZ-Mass relation, Gastrophysics, … Courtesy of John Carlstrom CMB Constraints on the Intracluster Medium

6. In the mean time … CMB Constraints on the Intracluster Medium

7. SZ detections in Cross-Correlationwith Galaxy/Cluster Surveys • Bennett et al. 2003 (XBAC’s clusters; 2.5) • Fosalba, Gaztanaga, & Castander 2003; Fosalba & Gaztanaga 2004 (SDSS, APM; 2.7) • Myers et al. 2004 (APM+ACO; ~2) • Afshordi, Loh, & Strauss 2004 (2MASS; 3.7) CMB Constraints on the Intracluster Medium

8. tSZ in 2MASSxWMAP Correlation Afshordi, Loh, & Strauss (2MASS Deepest magnitude bin): • data best fit model ISW SZ Point Sources • Cluster physics is mixed with cosmology, • and non-linear bias • Does not employ the non-Gaussianity of the signal  CMB Constraints on the Intracluster Medium

9. SZ detection based on SZ templates made out of Galaxy/Cluster Surveys • Hernandez-Monteagudo & Rubino-Martin 2004 (BCS, NORAS, etc; 2-5) • Hernandez-Monteagudo et al. 2004,2006 (2MASSxWMAP+Archeops; 5) • Does employ the non-Gaussianity of the signal  • Cluster physics is mixed with template making • procedure in a non-trivial manner  CMB Constraints on the Intracluster Medium

10. How to get the most physics out? • Most Galaxies are NOT in clusters • Most SZ signal comes from clusters thus… • The SZ detection is more significant if we just look around clusters  Make an SZ template • The S/N is maximized if the template matches the actual SZ profile  Constraint on the SZ profile Template CMB Constraints on the Intracluster Medium Observed Sky

11. WMAP SZ clusters … • Three close-by clusters in the 3yr cleaned map (Tegmark et al) Abell 1656 Abell 133 Abell 2319 CMB Constraints on the Intracluster Medium

12. Match-filter SZ detection in an X-ray cluster catalog • Compile a catalog of 116 low-z X-ray clusters with measured temperatures • Compile the X-ray estimated gas mass for most of them • ICM/ Point Source template: • NFW gravitational potential • Hydrostatic equilibrium • Polytropic equation of state Pgas/ (gas)eff; eff = 1.2 • Point sources follow DM profile CMB Constraints on the Intracluster Medium

13. Gas Fraction vs. Temperature (WMAP 1yr) • The mean gas fraction of ICM is 20-40 % less than cosmic budget: <fgas h> = 0.08 ± 0.01(ran) ± 0.01(sys) • Comparable S/N to higher resolution interferometers (e.g. OVRO/BIMA Grego et al. 2001) • X-ray gas mass estimates consistent with SZ estimates • Both X-ray and SZ gas mass estimates show an increasing trend with Tx • SZ observation • X-ray Observation CMB Constraints on the Intracluster Medium fgas = Mgas/Mtot , H0 = 100 h km/s/Mpc

14. Gas Fraction vs. Temperature (WMAP 1yr) CMB Constraints on the Intracluster Medium

15. 30 Pierpaoli & Perna 2004 Microwave Luminosity of Cluster Members 28 LPS(MK < -21) = (2.4 ± 0.8) x 1027 h-2 erg/s/Hz/galaxy -Most of the signal comes from Tx < 2 keV -Mainly Q-band (lowest frequency) -Similar to Milky Way and M31 Milky Way WMAP cluster sources 26 CMB Constraints on the Intracluster Medium

16. New Analysis (WMAP 3 years) • WMAP 3 years • Temperature: Q,V,W • Nres = 9 (pixel size ' 0.1 deg) • 417 clusters • meaured X-ray temperature CMB Constraints on the Intracluster Medium

17. Methodology • Find R200 for each cluster using M200-TX relation • Constrain pressure within spherical radial bins centered at: 0.25,0.5,1,2,4,8 x R200+ a central radio source: • Only consider pixels close to each cluster, with resolution degrading with distance  Makes covariance matrix tractable CMB Constraints on the Intracluster Medium Degraded Abell 2319 in Q-band Abell 2319 in Q-band

18. Temperature-Weighted Gas Fraction Q-band V-bandW-band Hydro-Simulations All Clusters TX > 5 keV; 144 Clusters No significant frequency dependence  No significant point source contamination CMB Constraints on the Intracluster Medium

19. Universal Pressure Profile TX > 5 keV; 144 Clusters • __ CDM/crit • __ Hydro-Simulations • __ WMAP Random Realization • WMAP best fit Prior: gas > 0 2' 110 for the simulated profiles  10.5 detection CMB Constraints on the Intracluster Medium

20. Total ICM gas fraction • __ Hydro-Simulations • __ WMAP Random Realization • WMAP best fit Cosmic Concordance: b/CDM = 0.20 ± 0.01 Scaled simulation to match SZ detection: b/CDM = 0.23 ± 0.02 (ran) ± 0.02 (sys) 11 model independent measurement of SZ CMB Constraints on the Intracluster Medium

21. The Moral • WMAP does contain information about the low-redshift universe • The way to extract this information is through combination with low-redshift surveys • For a non-Gaussian signal such as SZ, the optimum way to extract the signal is through generating an estimated signal template • Based on an analytic ICM model, we detect SZ signal at 8 and Point Sources at 3 (1st year) • A model-independent analysis of 3 year WMAP data with 144 massive clusters yields: • The first model independent universal pressure profile, closely follow dark matter • Prefers simulation results to null at » 11 • In comparison with simulations, constrains b/m at 11 level, consistent with the concordance model CMB Constraints on the Intracluster Medium

22. The best is yet to come … • In the run-up to high resolution SZ surveys, there is much more that can and should be learnt about ICM • Higher Resolution CMB/SZ surveys (Planck, SZA, APEX, SPT, …) will be able to significantly lower their effective cluster detection mass threshold thru combination with wide-angle X-ray cluster surveys (e.g., DUO) • X-ray and SZ surveys must be combined to provide reliable tests for models of Dark Energy or Cluster Physics CMB Constraints on the Intracluster Medium

23. Quest for the Optimum Template:Analytic Model of Intra-Cluster Medium • Simulations  NFW dark matter profile •  = 200: • Gravitational Potential: CMB Constraints on the Intracluster Medium

24. Quest for the Optimum Template:Analytic Model of Intra-Cluster Medium • Assume Polytropic Gas; eff =1.2 • Hydrostatic Equilibrium+Accretion Shock at rvir • Assume NFW distribution of point sources with flat spectrum, i.e. T /-2 ; One source per bright galaxy CMB Constraints on the Intracluster Medium

25. Quest for the Optimum Template:Analytic Model of Intra-Cluster Medium • Estimated X-ray temperature of the Cluster • Given the cosmology, eff, and cvir, the value of Tx fixes the ICM properties, e.g., the SZ flux: CMB Constraints on the Intracluster Medium